EXHIBIT
      G

    


    FORM
      OF
      LOCK-UP AGREEMENT

    


    May
      __,
      2007

    


    Each
      Purchaser referenced below:

    


    
      	 	
              Re:

            	
              Securities
                Purchase Agreement, dated as of May __, 2007 (the “Purchase Agreement”),
                between MSTI Holdings, Inc., a Delaware corporation (the “Company”)
                and the purchasers signatory thereto (each, a “Purchaser”
                and, collectively, the “Purchasers”)

            


    

     

    Ladies
      and Gentlemen:

     

    Defined
      terms not otherwise defined in this letter agreement (the “Letter
      Agreement”)
      shall
      have the meanings set forth in the Purchase Agreement. Pursuant to Section
      2.2
      of the Purchase Agreement and in satisfaction of a condition of the Company’s
      obligations under the Purchase Agreement, the undersigned irrevocably agrees
      with the Company that, from the date hereof until the 30th
      calendar
      day following the Effective Date (such period, the “Restriction
      Period”),
      the
      undersigned will not offer, sell, contract to sell, hypothecate, pledge or
      otherwise dispose of (or enter into any transaction which is designed to, or
      might reasonably be expected to, result in the disposition (whether by actual
      disposition or effective economic disposition due to cash settlement or
      otherwise) by the undersigned or any Affiliate of the undersigned or any person
      in privity with the undersigned or any Affiliate of the undersigned), directly
      or indirectly, including the filing (or participation in the filing) of a
      registration statement with the Commission in respect of, or establish or
      increase a put equivalent position or liquidate or decrease a call equivalent
      position within the meaning of Section 16 of the Exchange Act with respect
      to,
      any shares of Common Stock or Common Stock Equivalents beneficially owned,
      held
      or hereafter acquired by the undersigned (the “Securities”).
      Beneficial
      ownership shall be calculated in accordance with Section 13(d) of the Exchange
      Act. In order to enforce this covenant, the Company shall impose irrevocable
      stop-transfer instructions preventing the Transfer Agent from effecting any
      actions in violation of this Letter Agreement.

    


    The
      undersigned acknowledges that the execution, delivery and performance of this
      Letter Agreement is a material inducement to each Purchaser to complete the
      transactions contemplated by the Purchase Agreement and that each Purchaser
      (which shall be a third party beneficiary of this Letter Agreement) and the
      Company shall be entitled to specific performance of the undersigned’s
      obligations hereunder. The undersigned hereby represents that the undersigned
      has the power and authority to execute, deliver and perform this Letter
      Agreement, that the undersigned has received adequate consideration therefor
      and
      that the undersigned will indirectly benefit from the closing of the
      transactions contemplated by the Purchase Agreement. 

     

    This
      Letter Agreement may not be amended or otherwise modified in any respect without
      the written consent of each of the Company, each Purchaser and the undersigned.
      This Letter Agreement shall be construed and enforced in accordance with the
      laws of the State of New York without regard to the principles of conflict
      of
      laws. The undersigned hereby
      irrevocably submits to the exclusive jurisdiction of the United States District
      Court sitting in the Southern District of New York and the courts of the State
      of New York located in Manhattan, for the purposes of any suit, action or
      proceeding arising out of or relating to this Letter Agreement, and hereby
      waives, and agrees not to assert in any such suit, action or proceeding, any
      claim that (i) it is not personally subject to the jurisdiction of such court,
      (ii) the suit, action or proceeding is brought in an inconvenient forum, or
      (iii) the venue of the suit, action or proceeding is improper.
      The
      undersigned hereby irrevocably waives personal service of process and consents
      to process being served in any such suit, action or proceeding by receiving
      a
      copy thereof sent to the Company at the address in effect for notices to it
      under the Purchase Agreement and agrees that such service shall constitute
      good
      and sufficient service of process and notice thereof. The undersigned hereby
      waives any right to a trial by jury. Nothing contained herein shall be deemed
      to
      limit in any way any right to serve process in any manner permitted by law.
      The
      undersigned agrees and understands that this Letter Agreement does not intend
      to
      create any relationship between the undersigned and each Purchaser and that
      each
      Purchaser is not entitled to cast any votes on the matters herein contemplated
      and that no issuance or sale of the Securities is created or intended by virtue
      of this Letter Agreement.

     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    By
      its
      signature below, the Company’s Transfer Agent hereby acknowledges and agrees
      that, reflecting this Letter Agreement, it has placed an irrevocable stop
      transfer instruction on all Securities beneficially owned by the undersigned
      until the end of the Restriction Period. This Letter Agreement shall be binding
      on successors and assigns of the undersigned with respect to the Securities
      and
      any such successor or assign shall enter into a similar agreement for the
      benefit of the Purchasers.

    


    


    ***
      SIGNATURE PAGE FOLLOWS***

    


    
      
         

      

      
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    This
      Letter Agreement may be executed in two or more counterparts, all of which
      when
      taken together may be considered one and the same agreement.

     

    _________________________

    Signature

     

    __________________________

    Print
      Name

     

    __________________________

    Position
      in Company

    


    Address
      for Notice:

    


    
      __________________________


      __________________________

    

     

    
      __________________________

    

    Number
      of
      shares of Common Stock

    


    _____________________________________________________________________________

    Number
      of
      shares of Common Stock underlying subject to warrants, options, debentures
      or
      other convertible securities

     

    By
      signing below, the Company agrees to enforce the restrictions on transfer set
      forth in this Letter Agreement.

    


    MSTI
      HOLDINGS, INC.

     

    _________________________________   

    
 

    By: 

    
      
        

      

    

    Name:

    Title:

     

    Acknowledged
      and agreed to

    as
      of the
      date set forth above:

    


    [insert
      name of transfer agent]  

     

     

    By:
      

    
      
Name:

    Title: 

            

    
      
         

      

      
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