Girls pose during a photocall to promote the Big Royal Wedding Sleepover at “Camp Royale” on Clapham Common on March 8, 2011 in London, England. The “Pop Up” campsite will cater for up to 10,500 people between April 28 and May 1 to coincide with the weekend of the Royal Wedding on April 29. (Photo by Dan Kitwood/Getty Images). LONDON, ENGLAND – MARCH 08 2011

Customers try out the the new iPad2 shortly after it went on sale at the Fifth Avenue Apple store March 11, 2011 in New York City. The iPad 2 became available at 4:00 a.m. Eastern time for online purchase and at 5:00 p.m. today in over 10,000 retail locations.

David Reutimann, driver of the #00 Aaron's Dream Machine Toyota, Brian Vickers, driver of the #83 Red Bull Toyota, and Denny Hamlin, driver of the #11 FedEx Express Toyota, collide after an incident in the NASCAR Sprint Cup Series Jeff Byrd 500 Presented By Food City at Bristol Motor Speedway on March 20, 2011 in Bristol, Tennessee.

A CRH train is seen passing through Nanjing South Railway Station, which is part of the Beijing-Shanghai High-Speed Railway Line, on March 27, 2011 in Nanjing, Jiangsu Province of China. The High-Speed railway line is 1,318 kilometres long, running between Beijing and Shanghai. The line will open on June 10, 2011. (Photo by ChinaFotoPress/Getty Images)

A gallery assistant for Sotheby's auction house admires a melchior of Chateau Cheval Blanc 2006 on February 12, 2010 in London, England. The melchior sized bottle, which is 18 litres in volume, is to be sold in Sotheby's sale of “Finest and Rarest Wines & Vintage Port” on February 17, 2010 in London and is expected to fetch up to 4,800 GBP. (Photo by Oli Scarff/Getty Images)

Victoria's Secret angels Adriana Lima, Candice Swanepoel, Alessandra Ambrosio and Miranda Kerr arrive at the 2011 Victoria's Secret SWIM Collection Pink Carpet Event hosted by VS Angels at Club L on March 30, 2011 in Los Angeles, California. (Photo by Jerod Harris/Getty Images for Victoria's Secret)

Rescuers work at the traffic accident site on April 1, 2011 in Xi'an, Shaanxi province of China. A truck collided with a bus at a cross on Friday morning. As the truck headed for the sidewalk, it collided into a pedestrian and 6 vehicles which were stopped nearby. As a result 16 people were injuried, one currently has severe injuries. (Photo by ChinaFotoPress/Getty Images)

A Tibetan rider fires his weapon as he perfoms his riding skills at the Qinghai Yushu Horse Racing Festival on July 27, 2007 in Yushu County of Yushu Tibetan Autonomous Prefecture, Qinghai Province, northwest China. The Horse Racing Festival of Tibetan nomads in Yushu Prefecture falls in late July and early August on the Tibetan calendar. During the festival, various equestrian skills will be performed along with singing, dancing and costume shows. (Photo by China Photos/Getty Images)