After hours of intense bilateral meetings, even the president of America needs to take a break.And where best to relax with another of the world’s most powerful men than a burger joint?Barack Obama and Russian President Dmitry Medvedev were welcomed by customers' cheers as they ventured to Ray’s Hell Burger.Travelling by motorcade, they stopped for food at the diner in the Washington suburb of Arlington, Virginia, where Obama ate last year with Vice President Joe Biden.