In this file photo, actress Angelina Jolie, right, and actor Brad Pitt arrive before the 84th Academy Awards. At the London Olympics, Hollywood royalty such as Pitt and Jolie will be rubbing shoulders with diplomats and businessmen at the city's glitziest clubs and grandest historic buildings. (AP Photo/Amy Sancetta)

In this file photo, actress Nicole Kidman poses for photographers at the 65th international film festival. Hollywood royalty such as Kidman will be rubbing shoulders with diplomats and businessmen at the city's glitziest clubs and grandest historic buildings. (AP Photo/Lionel Cironneau)

British singer Dizzee Rascal performs on stage at the Olympic Torch Relay Concert in Hyde Park, central London, Thursday, July 26, 2012. (AP Photo/Joel Ryan)

British musician Mark Ronson performs on stage at the Olympic Torch Relay Concert in Hyde Park, central London, Thursday, July 26, 2012. (AP Photo/Joel Ryan)

This photo provided by Beyond Sport, shows boxing legend Muhammad Ali, center, with soccer player David Beckham, right, presenting a community service award to Matiullah Haidar on Tuesday July 24, 2012. (AP Photo/Action Images for Beyond Sport)

British singer Katy B performs on stage at the Olympic Torch Relay Concert in Hyde Park, central London, Thursday, July 26, 2012. (AP Photo/Joel Ryan)

British Prime Minister David Cameron talks to London 2012 Olympic and Paralympic Games volunteers during a visit to coincide with one month to go to the 2012 Games. (AP Photo/Lefteris Pitarakis, pool)

Republican presidential candidate, Mitt Romney walks out of 10 Downing Street after meeting with British Prime Minister David Cameron in London, Thursday, July 26, 2012. (AP Photo/Charles Dharapak)

First lady Michelle Obama speaking during a breakfast with Team USA at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Darron Cummings)