A New York window cleaner strapped to the side of The RCA Building in the Rockefeller Center, with St Patrick's Cathedral below him to the left. (Photo by William Lovelace/Express/Getty Images). 2nd May 1961

Space Shuttle Atlantis lands at the Kennedy Space Center July 21, 2011 in Cape Canaveral, Florida. The landing brings to a close the 30-year era of the space shuttle program that began in 1981, and has included 135 missions. (Photo by Bill Ingalls/NASA via Getty Images)

An Aerial view Admiralty Arch at the top of The Mall on July 26, 2011 in London, England. (Photo by Tom Shaw/Getty Images)

A detail of "Supersilvio" by Francesco De Molfetta representing the Italian Prime Minister Silvio Berlusconi is displayed during the MiArt 2011 Contemporary and Modern Art International Fair press preview on April 7, 2011 in Milan, Italy.

Racing fans soak up the sunshine and dress to impress during Ladies Day at the Aintree Grand National meeting on April 8, 2011 in Aintree, England. Friday is traditionally Ladies day at the three-day meeting of the world famous Grand National, where fashion is as important as the racing.

An oversized, prehistoric praying mantis wreaks havoc in a freeway underpass as it overturns cars and trucks, in a film still from “The Deadly Mantis”, directed by Nathan Juran, 1957. (Photo by Universal Pictures/Courtesy of Getty Images)

Workers sort freshly-painted Easter eggs at the Lueck poultry farm on April 7, 2011 in Sommerkahl near Aschaffenburg, Germany. The farm is currently working 24-hour shifts to meet demand for its brightly-coloured eggs two weeks before Easter. (Photo by Ralph Orlowski/Getty Images)

Blue Man Group founders Phil Stanton, Chris Wink and Matt Goldman pose for a photo at the Blue Man Group's 20th anniversary reunion show to benefit The Blue School at the Astor Theater on April 13, 2011 in New York City.