Anticipation builds for the Olympics opening ceremony

Revelers gather for the BT London Live Opening Ceremony Celebration Concert in Hyde Park in central London in the hours before the opening ceremony.  (Miguel Medina / AFP/Getty Images)

A patriotic British fan roams Olympic Park before the opening ceremony.   (Marius Becker / EPA)

A view from above Olympic Stadium hours before the opening ceremony.  (Alberto Pizzoli / AFP/Getty Images)

Scottish singer Paolo Nutini performs at the BT London Live Opening Ceremony Celebration Concert in Hyde Park.  (Miguel Medina / AFP/Getty Images)

American fans show their colors before the opening ceremony at Olympic Stadium.  (Michael Steele / Getty Images)

Queen Elizabeth chats with First Lady Michelle Obama and U.S. Ambassador to Britain Louis Susman at a Buckingham Palace reception for heads of state and other visiting dignitaries before the opening ceremony.  (Dominic Lipinski / AFP/Getty Images)

A woman arrives at Olympic Stadium for the opening ceremony wearing a hand-decorated hat featuring the Olympic rings and a cyclist.  (Franck Fife / AFP/Getty Images)

Kazakhstan supporters hold a pep rally before the opening ceremony at Olympic Stadium.  (Michael Steele / Getty Images)

Excitement builds for fans of the Mexican Olympic team before the opening ceremony.  (Hannibal / EPA)

A spectator sees the world through Union Jack glasses while waiting for the start of the opening ceremony at Olympic Stadium.  (Gabriel Bouys / AFP/Getty Images)

A cast of thousands, including animals and actors, enters the stadium for the British meadow scene before the opening ceremony.  (Franck Fife / AFP/Getty Images)