• Paul McCartney, center, performs during the Opening Ceremony at the 2012 Summer Olympics, Saturday, July 28, 2012, in London. (AP Photo/Matt Dunham, Pool)
  • The Olympic flag is carried by Daniel Barenboim, Sally Becker, Shami Chakrabati CBE, Leymah Gbowee, Haile Gebrselassie, Doreen Lawrence OBE, Ban Ki-moon and Marina Silva during the Opening Ceremony of the 2012 Olympic Summer Games at the Olympic Stadium in London, Saturday, July 28, 2012. (AP Photo/Ezra Shaw, Pool)
  • Fireworks explode over the stadium at the end of the Opening Ceremony of the 2012 Olympic Summer Games at the Olympic Stadium in London, Saturday, July 28, 2012. (AP Photo/ Ezra Shaw, Pool)
  • Fireworks explode over the stadium at the end of the Opening Ceremony of the 2012 Olympic Summer Games at the Olympic Stadium in London, Saturday, July 28, 2012. (AP Photo/ Ezra Shaw, Pool)
  • The Olympic torch is lit during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Lee Jin-man)
  • Steve Redgrave, right, holds the Olympic torch after entering the stadium during the Opening Ceremony at the 2012 Summer Olympics, Saturday, July 28, 2012, in London. (AP Photo/Matt Dunham, Pool)
  • The Olympic cauldron burns following the opening ceremonies to the 2012 Summer Olympics in London on Saturday, July 28, 2012. (AP Photo/The Canadian Press, Sean Kilpatrick)
  • Caster Semenya walks with the South African Flag during London Olympics Opening Ceremony at the Olympic Stadium on Friday, July 27, 2012 in London, England. (Roger Sedres, Gallo Images)
  • Smoke from fireworks surrounds the iconic Tower Bridge over the River Thames in central London, decorated with Olympic rings, during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Lefteris Pitarakis)
  • Performers dance during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Jae C. Hong)
  • A person dressed as Queen Elizabeth II parachutes into the Olympic stadium during the Opening Ceremony of the 2012 Olympic Summer Games at the Olympic Stadium in London, Friday, July 27, 2012. (AP Photo/Ezra Shaw, Getty)
  • Performers dance during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Matt Dunham)
  • Performers play drums during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Matt Dunham)
  • Actors perform in a sequence meant to represent Britain's National Health Service (NHS) perform during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Jae C. Hong)
  • The Olympic rings light up the stadium during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/David J. Phillip)
  • Actors perform during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Ivan Sekretarev)
  • Britain's Prince William, the Duke of Cambridge, back left, and his wife Catherine, Duchess of Cambridge, back right, Britain's Prime Minister David Cameron, front right, and his wife Samantha, front left, watch the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Matt Dunham)
  • The President of the International Olympic Committee Jacques Rogge, left, and Britain's Archbishop of Canterbury Rowan Williams, back right, applaud as Britain's Queen Elizabeth II, foreground right, arrives during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Matt Dunham)
  • Audience members holding LED panels light up the stadium during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/David J. Phillip)
  • Actors perform during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Morry Gash)
  • The Olympic rings are illuminated with pyrotechnics as they are raised above the stadium during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Jae C. Hong)
  • Actors perform during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Eric Gay)
  • Tour de France champion Bradley Wiggins ring a bell during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Charlie Riedel)
  • Performers make a circle during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Charlie Riedel)
  • Actors perform during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Ivan Sekretarev)
  • The Red Arrows make a flypast ahead of the Opening Ceremony of the 2012 Olympic Summer Games at the Olympic Stadium, London, Friday, July 27, 2012. (AP Photo/John Stillwell, pool)
  • Performers play a game of cricket during the Opening Ceremony at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Matt Dunham)
  • The Mayor of London Boris Johnson, left, and his wife Marina Wheeler arrive for the start of the Opening Ceremony of the 2012 Olympic Summer Games at the Olympic Stadium in London, Friday, July 27, 2012. (AP Photo/John Stillwell, pool)