Enthusiasts skate on a frozen fen in sub-zero temperatures on February 11, 2012 in Sutton, England. (Photo by Oli Scarff/Getty Images)

Whitney Houston's body arrives at Whigham Funeral Home on February 13, 2012 in Newark, New Jersey. (Photo by Dave Kotinsky/Getty Images)

Brazilians perform capoeira on the first day of Carnival celebrations on February 16, 2012 in Salvador, Brazil. Rio de Janiero's Carnival begins tomorrow. (Photo by Mario Tama/Getty Images)

A general view of the Burj Khalifa on February 23, 2012 in Dubai, United Arab Emirates. At 829.84 m (2723 ft) tall the Burj Khalifa is currently the tallest building in the world. (Photo by Chris Jackson/Getty Images)

Jimmy Fallon and Madonna sign the Facebook wall before their livestream interview at the Facebook offices on March 24, 2012 in New York City. (Photo by Dimitrios Kambouris/Getty Images)

New Zealand Paralympic swimmer Cameron Leslie poses for portrait at the Millennium Pool on March 26, 2012 in Auckland, New Zealand. (Photo by Hannah Johnston/Getty Images)

A Hawker Hurricane Mk XIIa 5711 (G-HURI) fighter aircraft prepares to perform an aerobatic display at the IWM Duxford on October 18, 2012 in Duxford, England. The aeroplane, similar to those that defended British shores during the Battle of Britain in World War II, is due to be auctioned by Bonhams in their sale of “Collectors' Motor Cars and Automobilia” at Mercedes-Benz World Brooklands on December 3, 2012. The plane was built in 1942 and joined the Royal Canadian Air Force the following year, where it remained for the duration of the war, it is expected to fetch up to 17 million GBP. (Photo by Oli Scarff)

Maj. Matt O'Donnell of Glenelg, MD shields himself from rotor wash as Ospreys carrying the delegation of U.S. Secretary of Defense Leon Panetta leaves on March 14, 2012 at Forward Operating Base Shukvani, Afghanistan. Panetta is also scheduled to meet with President Karzai during his two-day visit to Afghanistan. The trip comes as the Taliban has vowed revenge following this past weekend's killing spree by a U.S. soldier who is accused of killing 16 civilians in Afghanistan. Most of those killed were children and women. (Photo by Scott Olson/Getty Images)