President Obama (second from right), first lady Michelle Obama (second from left), Britain's Queen Elizabeth II (right) and Prince Philip tour the Queen's Gallery at Buckingham Palace in London on Tuesday, May 24, 2011. (AP Photo/Charles Dharapak)

Photo by: Charles Dharapak

President Obama (second from right), first lady Michelle Obama (second from left), Britain's Queen Elizabeth II (right) and Prince Philip tour the Queen's Gallery at Buckingham Palace in London on Tuesday, May 24, 2011. (AP Photo/Charles Dharapak)