Singer Rihanna performs at the Staples Center on June 28, 2011 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

Five year old Michael Esteban and his mother Kari Esteban, crawl through a 40-foot long, 4-foot high replica of a human colon on July 11, 2003 in Seattle. The colon is used to educate people on colorectal cancer. (Photo by Ron Wurzer/Getty Images)

Models promote a condom brand at the first Shenzhen s*x Culture Festival on September 21, 2007 in Shenzhen of Guangdong Province, China. The festival aims to increase awareness about reproductive health and popularise s*x education. (Photo by China Photos/Getty Images)

A soldier stands guard on the aircraft park of the Pyongyang Airport on April 3, 2011 in Pyongyang, North Korea. Pyongyang is the capital city of North Korea and the population is about 2,500,000.

Racegoers make their way home after Ladies Day on the second day of the Grand National meeting at Aintree Racecourse on April 9, 2010 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. (Photo by Christopher Furlong/Getty Images)

Dayang Nur Atikah, poses as she is announced as the winner of the Supermodel of the World Malaysia 2011 at Sepang International Circuit on April 10, 2011 in Kuala Lumpur, Malaysia. Dayang Nur Atikah, 18, will represent Malaysia at the 30th anniversary of the Ford Models Search in New York. (Photo by Syamsul Bahri Muhammad/Getty Images)

Two dogs sent into outer space by the Soviet Union after their safe return to earth. They spent 22 days in orbit. (Photo by Central Press/Getty Images). 22nd March 1966

Head of Global Marketing, Volkswagen Group Luca de Meo speaks onstage during the U.S. reveal of the 2012 Volkswagen Beetle at Pier 36 on April 18, 2011 in New York City. (Photo by Michael Loccisano/Getty Images for Volkswagen)