Katy Perry attends the European premiere of Katy Perry: «Part Of Me 3D» at Empire Leicester Square on July 3, 2012 in London, England. (Photo by Mike Marsland)

Former Soviet leader Mikhail Gorbachev attends the Gorby 80 Gala at the Royal Albert Hall on March 30, 2011 in London, England. The concert is to celebrate the 80th birthday of the former Soviet leader Mikhail Gorbachev.

Bikers ride along the High Street as they take part in the Ride Of Respect to raise money for service veterans on April 3, 2011 in Wootton Bassett, England. The ride, which involved 10,000 bikers and started at Hullavington airfield, aims to honour the people of Wootton Bassett and to raise money for the Afghan Heroes charity.

The Enigma coding machine used by the Germans in WWII on display at Bletchley Park National Code Centre, November 25, 2004 in Bletchley, England. (Photo by Ian Waldie/Getty Images)

Visitors to Kensington Gardens are reflected in Anish Kapoor's sculpture “C-Curve 2007” on September 27, 2010 in London, England. (Photo by Peter Macdiarmid/Getty Images)

Lady Gaga performs at Radio 1's Big Weekend 2011 at Carlisle Airport on May 15, 2011 in Carlisle, England. (Photo by Dave Hogan/Getty Images)

Ke$ha performs live on stage during the second day of the Wireless Festival at Hyde Park on July 2, 2011 in London, England. (Photo by Jim Dyson/Getty Images)

(L-R) Daniel Radcliffe, Emma Watson, J K Rowling and Rupert Grint attend the World Premiere of “Harry Potter And The Deathly Hallows: Part 1” held at The Odeon Leicester Square on November 11, 2010 in London, England. (Photo by Dave Hogan/Getty Images)