U.S. President Barack Obama during the official arrival ceremony at Buckingham Palace in London, Tuesday, May 24, 2011. (AP Photo/Charles Dharapak, Pool)
Photos: President Obama Receives Guard of Honor at Buckingham Palace
Photos: President Obama Receives Guard of Honor at Buckingham Palace
U.S. President Barack Obama during the official arrival ceremony at Buckingham Palace in London, Tuesday, May 24, 2011. (AP Photo/Charles Dharapak, Pool)