6 / 14

Serena Williams

Serena Williams of the United States waves to the crowd after defeating Caroline Wozniacki of Denmark in the Quarterfinals of Women's Singles Tennis on Day 6 of the London 2012 Olympic Games at Wimbledon on August 2, 2012 in London, England. (Photo by Clive Brunskill/Getty Images)

Unusual rituals of Olympians

A look at some of the pre-competition rituals and lucky charms that top Olympians use to help their chances. -- By Carla Thorpe, Yahoo! Sports