This photo of Barack Obama is United States Government work, and is therefore in the public domain. It was downloaded from the White House Flickr photostream.
The text on the page reads:
President Barack Obama delivers his State of the Union address in the House Chamber at the U.S. Capitol in Washington, D.C., Jan. 25, 2011. (Official White House Photo by Pete Souza)
This official White House photograph is being made available only for publication by news organizations and/or for personal use printing by the subject(s) of the photograph. The photograph may not be manipulated in any way and may not be used in commercial or political materials, advertisements, emails, products, promotions that in any way suggests approval or endorsement of the President, the First Family, or the White House.