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


                                  SCHEDULE 13G


                    Under the Securities Exchange Act of 1934




                          OTTAWA SAVINGS BANCORP, INC.
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                                (Name of Issuer)

                     Common Stock, par value $0.01 per share
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                         (Title of Class of Securities)

                                    68955R102
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                                 (CUSIP Number)

                                December 1, 2005
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             (Date of Event Which Requires Filing of this Statement)

Check the  appropriate box to designate the rule pursuant to which this Schedule
13G is filed:

               [ ] Rule 13d-1(b) 
               [X] Rule 13d-1(c) 
               [ ] 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).





CUSIP NO.    68955R102
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1.     Names of Reporting Persons.  Tyndall Capital Partners, L.P.
       I.R.S. Identification Nos. Of Above Persons (entities only):  13-3594570
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2.      Check the Appropriate Box if a Member of a Group (See Instructions)
        (a)                      (b)      
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3.      SEC Use Only
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4.      Citizenship or Place of Organization:   Delaware
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  Number of Shares Beneficially Owned    5.  Sole Voting Power         116,000*
    by Each Reporting Person With:           -----------------------------------
                                         6.  Shared Voting Power             0
                                             -----------------------------------
                                         7.  Sole Dispositive Power    116,000*
                                             -----------------------------------
                                         8.  Shared Dispositive Power        0
                                             -----------------------------------
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9.      Aggregate Amount Beneficially Owned by Each Reporting Person:   116,000*
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10.     Check if  the Aggregate Amount  in Row (9)  Excludes Certain Shares (See
        Instructions):   N/A
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11.     Percent of Class Represented by Amount in Row (9):   5.2%
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12.     Type of Reporting Person (See Instructions):   PN
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*    78,880 shares of Ottawa Savings Bancorp, Inc. common stock, par value $0.01
     per share (the  "Common  Stock"),  are owned by Tyndall  Partners,  L.P., a
     Delaware limited partnership ("Tyndall"). 37,120 shares of the Common Stock
     are owned by Tyndall  Institutional  Partners,  L.P.,  a  Delaware  limited
     partnership ("Tyndall  Institutional").  Tyndall Capital Partners,  L.P., a
     Delaware limited partnership, is the general partner of Tyndall and Tyndall
     Institutional,  and possesses sole power to vote and direct the disposition
     of all Common Stock held by Tyndall and Tyndall Institutional.





Item 1.

(a)  Name Of Issuer:   Ottawa Savings Bancorp, Inc.
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(b)  Address  of  Issuer's  Principal  Executive Offices:    925 LaSalle Street,
     Ottawa, Illinois  61350
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Item 2.

(a)  Name of Person Filing:  Tyndall Capital Partners, L.P.
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(b)  Address of Principal Business  Office  or,  if  none, Residence:
     599 Lexington Avenue, Suite 4100, New York, New York  10022
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(c)  Citizenship:  Tyndall Capital Partners, L.P. is a Delaware limited 
     partnership
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(d)  Title of Class of Securities:  Common Stock
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(e)  CUSIP Number:  68955R102
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Item  3.  If  this  statement  is  filed  pursuant to  Sections 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 (as of December 1, 2005):    116,000

         (b)    Percent of Class (as of December 1, 2005):                 5.2%

         (c)    Number of shares as to which the person has:

            (i)  Sole power to vote or to direct the vote:               116,000

           (ii)  Shared power to vote or to direct the vote:                   0

          (iii)  Sole power to dispose or to direct the disposition of:  116,000

           (iv)  Shared power to dispose or to direct the disposition of:      0





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.

         By signing  below,  I certify  that, to  the best  of my knowledge  and
belief, the securities  referred to above were not acquired and are not held for
the purpose of or with the effect of changing or influencing  the control of the
issuer of such  securities  and were not acquired and are not held in connection
with or as a participant in any transaction having that purpose or effect.


                                    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.


                                    December 9, 2005


                                    TYNDALL CAPITAL PARTNERS, L.P.

                                    By: Jeffrey Management, LLC, general partner


                                    By: /s/ Jeffrey S. Halis
                                        ----------------------------------------
                                            Jeffrey S. Halis, Sole Member


      Attention: Intentional misstatements or omissions of fact constitute
                Federal criminal violations (See 18 U.S.C. 1001)