Peter Swanston, chief executive of the London Mint Office, poses with a rare 1933 Double Eagle coin, exhibited at Goldsmith's Hall, London, March 2, 2012. Nearly half a million Double Eagles were minted in 1933 during the Great Depression, but most of them were melted down before leaving the United States Mint as part of a strategy to stabilize the American economy. In 2002, a Double Eagle sold at auction for $7.6 million. (Peter Macdiarmid/Getty Images)

Brooke Hill helps a friend salvage and clean up what they can from her home, March 1, 2012, in Harrisburg, Ill. A pre-dawn tornado flattened entire blocks of homes Wednesday as violent storms ravaged the Midwest and South. (Seth Perlman/AP Photo)

Greg Cook hugs his dog Coco after finding her inside his destroyed home in East Limestone, Ala., March 2, 2012. A reported tornado destroyed several houses in northern Alabama as storms threatened more twisters across the region Friday. (Gary Cosby Jr./The Decatur Daily/AP Photo)

Yola, a long-tailed macaque, rides a small motorcycle during a street performance in Balikpapan, East Kalimantan, Indonesia, March 2, 2012. Animal charities such as the Jakarta Animal Aid Network are trying to ban the practice of street circus performances, calling it cruel and a violation of animal rights. (Yuli Seperi/Getty Images)

Prince Charles fires a paintball gun as he visits the Welsh Guards at Cavalry Barracks to mark St. David's Day in Hounslow, England, March 1, 2012. (Anwar Hussein/WireImage/Getty Images)

NYSE Executive Vice President Scott Cutler, right, uses his mobile phone to photograph Jeremy Stoppelman, center, Yelp co-founder and CEO, flanked by Yelp's COO Geoff Donaker, left, and CFO Rob Krolik, right center, during the company's IPO on the floor of the New York Stock Exchange March 2, 2012. (Richard Drew/AP Photo)

Iranian women line up to vote outside a polling station at the Massoumeh shrine in Qum, Iran, March 2, 2012. The balloting for the 290-member parliament is the first major voting since the disputed re-election of President Mahmoud Ahmadinejad in June 2009 and the mass protests and crackdowns that followed. (Majid Saeedi/Getty Images)

An aircraft creates a contrail as it flies over a blanket of clouds above Krakow, Poland, March 2, 2012. (Ferdinand Ostrop/AP Photo)

Artist Yvette Mattern shows her laser rainbow projection, Global Rainbow, in Whitley Bay, England, March 1, 2012. The light installation celebrates the London 2012 Cultural Olympiad in northeast England. The Global Rainbow has previously lit up the skies of Germany, France and the United States. (Bethany Clarke/Getty Images)