London Olympics

A visitor to Olympic Park stands with a United States flag under a set of Olympic rings at the 2012 Summer Olympics Saturday, Aug. 11, 2012, in London. (AP Photo/Charlie Riedel)

London Olympics

Visitors watch a broadcast of Olympic competitions on a big screen television at the Olympic Park during the 2012 Summer Olympics, Monday, July 30, 2012, in London. (AP Photo/Emilio Morenatti)

London riots

London's Run

Runners take part in the fourth-annual London's run at Schnepf Farms in Queen Creek, with proceeds going to children's cancer charities. Jan. 31, 2009.

London Olympics Swimming

United States' Breeja Larson competes in the women's 100-meter breaststroke swimming final at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London, Monday, July 30, 2012. (AP Photo/Michael Sohn)

London Olympics Swimming Women

United States' Missy Franklin poses with her gold medal in the women's 200-meter backstroke final during the men's 50-meter freestyle final at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London, Friday, Aug. 3, 2012. (AP Photo/Mark J. Terrill)

London Olympics Swimming Women

United States' women's 4 x 100-meter medley relay team members from left, Missy Franklin, Rebecca Soni, Dana Vollmer, and Alison Schmitt hold their gold medals on the podium at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London, Saturday, Aug. 4, 2012. (AP Photo/Michael Sohn)

London Olympics Closing Ceremony

Victoria Beckham of the the British pop group Spice Girls performs during the Closing Ceremony at the 2012 Summer Olympics, Sunday, Aug. 12, 2012, in London. (AP Photo/Martin Meissner)

London Olympics Closing Ceremony

British singer Annie Lennox performs "Little Bird" during the Closing Ceremony at the 2012 Summer Olympics, Sunday, Aug. 12, 2012, in London. (AP Photo/Sergei Grits)

London Olympics Closing Ceremony

British singer Jessie J, second left, performs during the Closing Ceremony at the 2012 Summer Olympics, Sunday, Aug. 12, 2012, in London. (AP Photo/Matt Slocum)

London Olympics Closing Ceremony

Posh Spice of the the British pop group Spice Girls performs during the Closing Ceremony at the 2012 Summer Olympics, Sunday, Aug. 12, 2012, in London. (AP Photo/Martin Meissner)

London Olympics Closing Ceremony

Fatboy Slim performs during the Closing Ceremony at the 2012 Summer Olympics, Sunday, Aug. 12, 2012, in London. (AP Photo/Kristy Wigglesworth)

London Olympics Closing Ceremony

Annie Lennox performs during the Closing Ceremony at the 2012 Summer Olympics, Sunday, Aug. 12, 2012, in London. (AP Photo/Charlie Riedel)

London Olympics Closing Ceremony

The Who's "Pinball Wizard" is performed by the Kaiser Chiefs during the Closing Ceremony at the 2012 Summer Olympics, Sunday, Aug. 12, 2012, in London. (AP Photo/David J. Phillip)

London Olympics Closing Ceremony

British singer Jessie J performs during the Closing Ceremony at the 2012 Summer Olympics, Sunday, Aug. 12, 2012, in London. (AP Photo/Jae C. Hong)

London Olympics Closing Ceremony

George Michael performs during the Closing Ceremony at the 2012 Summer Olympics, Sunday, Aug. 12, 2012, in London. (AP Photo/Martin Meissner)

London Olympics Closing Ceremony

Performers wave the British flag during the Closing Ceremony at the 2012 Summer Olympics, Sunday, Aug. 12, 2012, in London. (AP Photo/Sergei Grits)

London Olympics the Party is On

FILE - In this Feb. 7, 2010 file photo Roger Daltrey, left, Zak Starkey, center, and Pete Townshend of The Who perform during halftime of the NFL Super Bowl XLIV football game between the Indianapolis Colts and New Orleans Saints in Miami. (AP Photo/David J. Phillip, File)

London Olympics Weightlifting Women

United States' Sarah Robles reacts following a lift during women's +75-kg, weightlifting competition at the 2012 Summer Olympics, Sunday, Aug. 5, 2012, in London. (AP Photo/Hassan Ammar)

London Olympics Athletics Men

South Africa's Oscar Pistorius competes in a men's 400-meter heat during the athletics in the Olympic Stadium at the 2012 Summer Olympics, London, Saturday, Aug. 4, 2012. (AP Photo/Matt Dunham)

London Olympics Swimming Women

United States' 4 x 100-meter medley relay team from left, Allison Schmitt, Dana Vollmer, Rebecca Soni and Missy Franklin pose with their gold medals at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London, Saturday, Aug. 4, 2012. (AP Photo/Lee Jin-man)

London Olympics Swimming

United States' Michael Phelps holds the gold medal in the men's 4 X 100-meter medley relay at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London, Saturday, Aug. 4, 2012. (AP Photo/Matt Slocum)

London Olympics Athletics Women

Britain's Jessica Ennis celebrates winning the gold in the women's heptathlon during athletics competition in the Olympic Stadium at the 2012 Summer Olympics, Saturday, Aug. 4, 2012, in London. (AP Photo/David J. Phillip )

London Olympics Swimming Women

United States' Missy Franklin, left, and Elizabeth Beisel react after their first and third place wins in the women's 200-meter backstroke final at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London, Friday, Aug. 3, 2012. (AP Photo/Michael Sohn)