U.S. President Barack Obama walks from Marine One helicopter on the South Lawn of the White House in Washington D.C., capital of the United States, after he and his family returned from Camp David, March 29, 2009. [Zhang Yan/Xinhua]

U.S. President Barack Obama leans over to talk to his daughters Malia (C) and Sasha at the start of the White House Easter Egg Roll on the South Lawn of the White House in Washington April 13, 2009. [Zhang Yan/Xinhua]