POWER OF ATTORNEY
        KNOW ALL PERSONS BY THESE PRESENTS that the person whose signature 
appears below does hereby make, constitute and appoint each of A. William Stein, Joshua 
A. Mills and Barbara Polster as a true and lawful attorney-in-fact of the undersigned with 
full powers of substitution and revocation, for and in the name, place and stead of the 
undersigned (both in the undersigned's individual capacity and as an officer or member 
of the  board of directors) to execute and deliver such forms as may be required to be 
filed from time to time with the Securities and Exchange Commission with respect to any 
investments of Digital Realty Trust Inc. (including any amendments or supplements to 
any reports from schedules previously filed by such persons or entities) including any 
joint filing agreements or joint filer information statements in connection therewith, with 
respect to any subsidiary of Digital Realty Trust, Inc.: (i) pursuant to Sections 13(d) and 
16(a) of the Securities Exchange Act of 1934, as amended, including without limitation 
Schedules 13D and 13G, statements on Form 3, Form 4 and Form 5 and (ii) in connection 
with any applications for EDGAR access codes, including without limitation the Form 
ID.
/s/ Michael F. Foust                        
Chief Executive Officer
December 11, 2006