Celebrities attend White House Correspondents' Association Dinner

Diane Keaton walks on the red carpet for the annual White House Correspondents' Association Dinner at the Washington Hilton in Washington, April 28, 2012. [Photo/Agencies]

Former U.S. Secretary of State Colin Powell arrives on the red carpet for the annual White House Correspondents' Association Dinner at the Washington Hilton in Washington, April 28, 2012. [Photo/Agencies]