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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                  SCHEDULE 13G

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934

                                 (RULE 13d-102)

                 INFORMATION TO BE INCLUDED IN STATEMENTS FILED
          PURSUANT TO RULE 13D-1(b)(c), AND (d) AND AMENDMENTS THERETO
                         FILED PURSUANT TO RULE 13d-2(b)

                                 Callwave, Inc.
--------------------------------------------------------------------------------
                                (Name of Issuer)

                         Common Stock, $.0001 par value
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                   13126N 10 1
               --------------------------------------------------
                                 (CUSIP Number)

                                December 31, 2004
--------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

        |_|  Rule 13d-1(b)

        |_|  Rule 13d-1(c)

        |X|  Rule 13d-1(d)

          * The remainder of this cover page shall be filled out for a reporting
person's  initial  filing on this  form with  respect  to the  subject  class of
securities,  and for any subsequent amendment containing information which would
alter the disclosures provided in a prior cover page.

          The information required in the remainder of this cover page shall not
be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise  subject to the  liabilities of that section of
the Act but shall be subject to all other  provisions of the Act  (however,  see
the Notes).

                               Page 1 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1
--------------------------------------------------------------------------------

    1.   Names of Reporting Persons.
         I.R.S. Identification Nos. of above persons (entities only).

         Insight Venture Partners IV, L.P.
         52-2269503
         .......................................................................
--------------------------------------------------------------------------------

    2.   Check the Appropriate Box if a Member of a Group (See Instructions)

         (a)
             ...................................................................

         (b)   
             ...................................................................
--------------------------------------------------------------------------------
    3.   SEC Use 
         Only ..................................................................
--------------------------------------------------------------------------------
    4.   Citizenship or Place of Organization     Delaware
                                                 ...............................
--------------------------------------------------------------------------------
                           5. Sole Voting 
                              Power           2,395,490
                                             ...................................
                         -------------------------------------------------------
  Number of Shares         6.  Shared Voting 
  Beneficially                 Power
  Owned by Each                            .....................................
  Reporting Person       -------------------------------------------------------
  With:                    7. Sole Dispositive 
                              Power          2,395,490
                                             ...................................
                         -------------------------------------------------------
                           8. Shared Dispositive 
                              Power
                                             ...................................
--------------------------------------------------------------------------------
    9.   Aggregate Amount Beneficially Owned by Each 
         Reporting Person                    2,395,490
                                           .....................................

   10.   Check box if the Aggregate Amount in Row (9) Excludes 
         Certain Shares (See Instructions)
                                           .....................................

   11.   Percent of Class Represented by Amount in 
         Row (9)                            12.4%
                                           .....................................
--------------------------------------------------------------------------------
   12.   Type of Reporting Person (See Instructions)
--------------------------------------------------------------------------------
   PN
................................................................................

................................................................................

................................................................................

................................................................................

................................................................................

................................................................................

--------------------------------------------------------------------------------

                               Page 2 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1
--------------------------------------------------------------------------------

    1.   Names of Reporting Persons.
         I.R.S. Identification Nos. of above persons (entities only).

         Insight Venture Partners IV (Co-Investors), L.P.
         52-2269509
         .......................................................................
--------------------------------------------------------------------------------

    2.   Check the Appropriate Box if a Member of a Group (See Instructions)

         (a)
             ...................................................................

         (b)    
             ...................................................................
--------------------------------------------------------------------------------
    3.   SEC Use 
         Only ..................................................................
--------------------------------------------------------------------------------
    4.   Citizenship or Place of Organization     Delaware
                                                 ...............................
--------------------------------------------------------------------------------
                           5. Sole Voting 
                              Power           320,256
                                             ...................................
                         -------------------------------------------------------
  Number of Shares         6.  Shared Voting 
  Beneficially                 Power
  Owned by Each                            .....................................
  Reporting Person       -------------------------------------------------------
  With:                    7. Sole Dispositive 
                              Power          320,256
                                             ...................................
                         -------------------------------------------------------
                           8. Shared Dispositive 
                              Power
                                             ...................................
--------------------------------------------------------------------------------
    9.   Aggregate Amount Beneficially Owned by Each 
         Reporting Person                    320,256
                                           .....................................

   10.   Check box if the Aggregate Amount in Row (9) Excludes 
         Certain Shares (See Instructions)
                                           .....................................

   11.   Percent of Class Represented by Amount in 
         Row (9)                            1.7%
                                           .....................................
--------------------------------------------------------------------------------
   12.   Type of Reporting Person (See Instructions)
--------------------------------------------------------------------------------
   PN
................................................................................

................................................................................

................................................................................

................................................................................

................................................................................

................................................................................

--------------------------------------------------------------------------------


                               Page 3 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1
--------------------------------------------------------------------------------

    1.   Names of Reporting Persons.
         I.R.S. Identification Nos. of above persons (entities only).

         Insight Venture Partners IV (Fund B), L.P.
         52-2269507
         .......................................................................
--------------------------------------------------------------------------------

    2.   Check the Appropriate Box if a Member of a Group (See Instructions)

         (a)
             ...................................................................

         (b)    
             ...................................................................
--------------------------------------------------------------------------------
    3.   SEC Use 
         Only ..................................................................
--------------------------------------------------------------------------------
    4.   Citizenship or Place of Organization     Delaware
                                                 ...............................
--------------------------------------------------------------------------------
                           5. Sole Voting 
                              Power           295,217
                                             ...................................
                         -------------------------------------------------------
  Number of Shares         6.  Shared Voting 
  Beneficially                 Power
  Owned by Each                            .....................................
  Reporting Person       -------------------------------------------------------
  With:                    7. Sole Dispositive 
                              Power          295,217
                                             ...................................
                         -------------------------------------------------------
                           8. Shared Dispositive 
                              Power
                                             ...................................
--------------------------------------------------------------------------------
    9.   Aggregate Amount Beneficially Owned by Each 
         Reporting Person                    295,217
                                           .....................................

   10.   Check box if the Aggregate Amount in Row (9) Excludes 
         Certain Shares (See Instructions)
                                           .....................................

   11.   Percent of Class Represented by Amount in 
         Row (9)                            1.5%
                                           .....................................
--------------------------------------------------------------------------------
   12.   Type of Reporting Person (See Instructions)
--------------------------------------------------------------------------------
   PN
................................................................................

................................................................................

................................................................................

................................................................................

................................................................................

................................................................................

--------------------------------------------------------------------------------

                               Page 4 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1
--------------------------------------------------------------------------------

    1.   Names of Reporting Persons.
         I.R.S. Identification Nos. of above persons (entities only).

         Insight Venture Partners (Cayman) IV, L.P.
         90-0183706
         .......................................................................
--------------------------------------------------------------------------------

    2.   Check the Appropriate Box if a Member of a Group (See Instructions)

         (a)
             ...................................................................

         (b)    
             ...................................................................
--------------------------------------------------------------------------------
    3.   SEC Use 
         Only ..................................................................
--------------------------------------------------------------------------------
    4.   Citizenship or Place of Organization     Cayman Islands
                                                 ...............................
--------------------------------------------------------------------------------
                           5. Sole Voting 
                              Power           19,033
                                             ...................................
                         -------------------------------------------------------
  Number of Shares         6.  Shared Voting 
  Beneficially                 Power
  Owned by Each                            .....................................
  Reporting Person       -------------------------------------------------------
  With:                    7. Sole Dispositive 
                              Power          19,033
                                             ...................................
                         -------------------------------------------------------
                           8. Shared Dispositive 
                              Power
                                             ...................................
--------------------------------------------------------------------------------
    9.   Aggregate Amount Beneficially Owned by Each 
         Reporting Person                    19,033
                                           .....................................

   10.   Check box if the Aggregate Amount in Row (9) Excludes 
         Certain Shares (See Instructions)
                                           .....................................

   11.   Percent of Class Represented by Amount in 
         Row (9)                            .0001%
                                           .....................................
--------------------------------------------------------------------------------
   12.   Type of Reporting Person (See Instructions)
--------------------------------------------------------------------------------
   PN
................................................................................

................................................................................

................................................................................

................................................................................

................................................................................

................................................................................

--------------------------------------------------------------------------------

                               Page 5 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1
--------------------------------------------------------------------------------

    1.   Names of Reporting Persons.
         I.R.S. Identification Nos. of above persons (entities only).

         Insight Venture Associates IV, LLC
         37-1417641
         .......................................................................
--------------------------------------------------------------------------------

    2.   Check the Appropriate Box if a Member of a Group (See Instructions)

         (a)
             ...................................................................

         (b)    
             ...................................................................
--------------------------------------------------------------------------------
    3.   SEC Use 
         Only ..................................................................
--------------------------------------------------------------------------------
    4.   Citizenship or Place of Organization     Delaware
                                                 ...............................
--------------------------------------------------------------------------------
                           5. Sole Voting 
                              Power           
                                             ...................................
                         -------------------------------------------------------
  Number of Shares         6.  Shared Voting 
  Beneficially                 Power         3,029,996
  Owned by Each                            .....................................
  Reporting Person       -------------------------------------------------------
  With:                    7. Sole Dispositive 
                              Power          
                                             ...................................
                         -------------------------------------------------------
                           8. Shared Dispositive 
                              Power           3,029,996
                                             ...................................
--------------------------------------------------------------------------------
    9.   Aggregate Amount Beneficially Owned by Each 
         Reporting Person                    3,029,996
                                           .....................................

   10.   Check box if the Aggregate Amount in Row (9) Excludes 
         Certain Shares (See Instructions)
                                           .....................................

   11.   Percent of Class Represented by Amount in 
         Row (9)                            15.7%
                                           .....................................
--------------------------------------------------------------------------------
   12.   Type of Reporting Person (See Instructions)
--------------------------------------------------------------------------------
   00
................................................................................

................................................................................

................................................................................

................................................................................

................................................................................

................................................................................

--------------------------------------------------------------------------------

                               Page 6 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1
--------------------------------------------------------------------------------

    1.   Names of Reporting Persons.
         I.R.S. Identification Nos. of above persons (entities only).

         Insight Holdings Group, LLC
         35-2158588
         .......................................................................
--------------------------------------------------------------------------------

    2.   Check the Appropriate Box if a Member of a Group (See Instructions)

         (a)
             ...................................................................

         (b)    
             ...................................................................
--------------------------------------------------------------------------------
    3.   SEC Use 
         Only ..................................................................
--------------------------------------------------------------------------------
    4.   Citizenship or Place of Organization     
                                                 ...............................
--------------------------------------------------------------------------------
                           5. Sole Voting 
                              Power           
                                             ...................................
                         -------------------------------------------------------
  Number of Shares         6.  Shared Voting 
  Beneficially                 Power         3,029,996
  Owned by Each                            .....................................
  Reporting Person       -------------------------------------------------------
  With:                    7. Sole Dispositive 
                              Power          
                                             ...................................
                         -------------------------------------------------------
                           8. Shared Dispositive 
                              Power           3,029,996
                                             ...................................
--------------------------------------------------------------------------------
    9.   Aggregate Amount Beneficially Owned by Each 
         Reporting Person                    3,029,996
                                           .....................................

   10.   Check box if the Aggregate Amount in Row (9) Excludes 
         Certain Shares (See Instructions)
                                           .....................................

   11.   Percent of Class Represented by Amount in 
         Row (9)                            15.7%
                                           .....................................
--------------------------------------------------------------------------------
   12.   Type of Reporting Person (See Instructions)
--------------------------------------------------------------------------------
   00
................................................................................

................................................................................

................................................................................

................................................................................

................................................................................

................................................................................

--------------------------------------------------------------------------------

                               Page 7 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1

ITEM 1.


         (A)   NAME OF ISSUER:

               Callwave, Inc.

         (B)   ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:

               136 West Canon Perdido Street
               Santa Barbara, CA 93101

ITEM 2.

               NAME OF PERSON FILING:

               Insight Venture Partners IV, L.P. ("IVP")
               Insight Venture Partners IV (Co-Investors), L.P. ("IVP 
               Co-Investors")
               Insight Venture Partners (Fund B), L.P. ("IVP Fund B")
               Insight Venture Partners (Cayman) IV. , L.P. ("IVP Cayman")
               Insight Venture Associates IV, LLC ("Associates")
               Insight Holdings Group, LLC ("Holdings")

               Supplemental information relating to the ownership and control of
               the person filing this statement is included in Exhibit 2(a)
               attached hereto.

         (A)   ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE:

               c/o Insight Capital Partners
               680 Fifth Avenue, 9th Floor
               New York, NY 10019

         (B)   CITIZENSHIP:

               For all Reporting Persons (other than IVP Cayman): Delaware
               IVP Cayman: Cayman Islands

         (C)   TITLE OF CLASS OF SECURITIES (OF ISSUER):

               Common Stock, $.0001 par value

         (D)   CUSIP NUMBER:

               13126N 10 1

ITEM 3.  IF THIS STATEMENT IS FILED PURSUANT TO SS.SS. 240. 13d-1(b) OR 
         240. 13D-2(b) or (c), CHECK WHETHER THE PERSON FILING IS A:

               Not Applicable

ITEM 4.  OWNERSHIP

         (A)   AMOUNT BENEFICIALLY OWNED:

               IVP             :       2,395,490
               IVP Co-Investors:         320,256
               IVP Fund B      :         295,217
               IVP Cayman      :          19,033
               Associates      :       3,029,996
               Holdings        :       3,209,996


                               Page 8 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1

         (B)   PERCENT OF CLASS:

               IVP             :        12.4%
               IVP Co-Investors:         1.7%
               IVP Fund B      :         1.5%
               IVP Cayman      :       .0001%
               Associates      :        15.7%
               Holdings        :        15.7%

         (C)   NUMBER OF SHARES AS TO WHICH SUCH PERSON HAS:

               (i)    Sole power to vote: IVP: 2,395,490, IVP Co-Investors:
                      320,256, IVP Fund B: 295,217, IVP Cayman: 19,033,
                      Associates: 0, Holdings: 0

               (ii)   Shared power to vote: IVP: 0, IVP Co-Investors:0, IVP Fund
                      B: 0, IVP Cayman: 0, Associates: 3,029,996, Holdings:
                      3,029,996

               (iii)  Sole power to dispose: IVP: 2,395,490, IVP Co-Investors:
                      320,256, IVP Fund B: 295,217, IVP Cayman: 19,033,
                      Associates: 0, Holdings: 0

               (iv)   Shared power to dispose: IVP: 0, IVP Co-Investors:0, IVP
                      Fund B: 0, IVP Cayman: 0, Associates: 3,029,996, Holdings:
                      3,029,996

ITEM 5.  OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS

         Not applicable

ITEM 6.  OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON

               Not applicable.

ITEM 7.  IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE 
         SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY

               Not applicable.

ITEM 8.  IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP

               Not applicable.

ITEM 9.  NOTICE OF DISSOLUTION OF GROUP

               Not applicable.

ITEM 10. CERTIFICATION

               Not applicable

                               Page 9 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1

                                    SIGNATURE

                  After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this statement is true,
complete and correct.

Date:  February 14, 2005

                              INSIGHT VENTURE PARTNERS IV, L.P.

                              By:  Insight Venture Associates IV, LLC, its
                              general partner



                              By: /s/ Deven Parekh
                                  ----------------------------------------------
                                  Name:  Deven Parekh
                                  Title: Managing Director


                              INSIGHT VENTURE PARTNERS IV (CO-INVESTORS), L.P.

                              By:  Insight Venture Associates IV, LLC, its
                              general partner


                              By: /s/ Deven Parekh 
                                  ----------------------------------------------
                                  Name:  Deven Parekh
                                  Title: Managing Director
                              

                              INSIGHT VENTURE PARTNERS IV (FUND B), L.P.

                              By: Insight Venture Associates IV, LLC, its
                              general partner



                              By: /s/ Deven Parekh
                                  ----------------------------------------------
                                  Name:  Deven Parekh
                                  Title: Managing Director


                              INSIGHT VENTURE PARTNERS (CAYMAN) IV, L.P.

                              By: Insight Venture Associates IV, LLC, its
                              general partner



                              By: /s/ Deven Parekh
                                  ----------------------------------------------
                                  Name:  Deven Parekh
                                  Title: Managing Director


                               Page 10 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1


                              INSIGHT VENTURE ASSOCIATES, LLC



                              By: /s/ Deven Parekh
                                  ----------------------------------------------
                                  Name:  Deven Parekh
                                  Title: Managing Director
                              

                              INSIGHT HOLDINGS GROUP, LLC



                              By: /s/ Deven Parekh
                                  ----------------------------------------------
                                  Name:  Deven Parekh
                                  Title: Managing Director






                               Page 11 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1

                                  EXHIBIT 2(A)

          This Statement is being filed by Insight Venture  Partners IV, L.P., a
Delaware limited partnership (hereinafter referred to as "IVP"), Insight Venture
Partners IV (Co-Investors),  L.P., a Delaware limited  partnership  (hereinafter
referred to as "IVP Co-Investor"),  Insight Venture Partners (Cayman), IV, L.P.,
a Cayman Islands limited partnership  (hereinafter referred to as "IVP Cayman"),
Insight  Venture  Partners IV (Fund B),  L.P.,  a Delaware  limited  partnership
(hereinafter  referred to as "IVP Fund B"), Insight Venture  Associates,  LLC, a
Delaware limited liability company (hereinafter referred to as "Associates") and
Insight Holdings Group, LLC, a Delaware limited  liability company  (hereinafter
referred  to as  "Holdings")  each of whose  principal  office is located at c/o
Insight Capital Partners IV, L.P., 527 Madison Avenue, 10th Floor, New York, New
York, 10022. Each of IVP,  Co-Investor,  IVP Cayman and IVP Fund B (collectively
referred to herein as the  "Insight  Funds") is engaged in the  venture  capital
business.  Each of  Associates  and  Holdings is engage in the  Venture  Capital
business indirectly through the Insight Funds.

          Associates is the general partner of each of the Insight Funds, and as
such may be deemed to be the beneficial  owner of all shares held by the Insight
Funds.

          Holdings  is the  managing  member of  Associates,  and as such may be
deemed to be the beneficial  owner of all shares held by the Insights Funds. The
managing  directors  of  Holdings  are [Deven  Parekh,  Scott  Maxwell,  Jeffrey
Horing, Peter Sobiloff and Jerry Murdock].







                               Page 12 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1

                                  EXHIBIT 2(B)

                             JOINT FILING AGREEMENT

         The undersigned acknowledge and agree that the foregoing statement on
Schedule 13G is filed on behalf of each of the undersigned and that all
subsequent amendments to this statement on Schedule 13G shall be filed on behalf
of each of the undersigned without the necessity of filing additional joint
acquisition statements. The undersigned acknowledge that each shall be
responsible for the timely filing of such amendments, and for the completeness
and accuracy of the information concerning him or it contained therein, but
shall not be responsible for the completeness and accuracy of the information
concerning the other, except to the extent that he or it knows or has reason to
believe that such information is accurate.

Dated this 14th day of February, 2005.


                              INSIGHT VENTURE PARTNERS IV, L.P.

                              By:  Insight Venture Associates IV, LLC, its
                              general partner

                              By:  Insight Holdings Group, LLC., its managing
                              member


                              By: /s/ Deven Parekh
                                  ----------------------------------------------
                                  Name:  Deven Parekh
                                  Title: Managing Director


                              INSIGHT VENTURE PARTNERS IV (CO-INVESTORS), L.P.

                              By:  Insight Venture Associates IV, LLC, its
                              general partner

                              By:  Insight Holdings Group, LLC., its managing
                              member


                              By: /s/ Deven Parekh
                                  ----------------------------------------------
                                  Name:  Deven Parekh
                                  Title: Managing Director


                              INSIGHT VENTURE PARTNERS IV (FUND B), L.P.

                              By: Insight Venture Associates IV, LLC, its
                              general partner

                              By:  Insight Holdings Group, LLC., its managing
                              member


                              By: /s/ Deven Parekh
                                  ----------------------------------------------
                                  Name:  Deven Parekh
                                  Title: Managing Director


                               Page 13 of 14 pages



                                  SCHEDULE 13G

ISSUER:  Callwave, Inc.                                  CUSIP NO.:  13126N 10 1


                              INSIGHT VENTURE PARTNERS (CAYMAN) IV, L.P.

                              By: Insight Venture Associates IV, LLC, its
                              general partner

                              By:  Insight Holdings Group, LLC., its managing
                              member


                              By: /s/ Deven Parekh
                                  ----------------------------------------------
                                  Name:  Deven Parekh
                                  Title: Managing Director


                              INSIGHT VENTURE ASSOCIATES, LLC

                              By:  Insight Holdings Group, LLC., its managing
                              member


                              By: /s/ Deven Parekh
                                  ----------------------------------------------
                                  Name:  Deven Parekh
                                  Title: Managing Director


                              INSIGHT HOLDINGS GROUP, LLC


                              By: /s/ Deven Parekh
                                  ----------------------------------------------
                                  Name:  Deven Parekh
                                  Title: Managing Director




                               Page 14 of 14 pages