** FILE ** Australian swimmer Ian Thorpe holds his gold medal from the men's 400m freestyle at the Sydney International Aquatic Centre during the Summer Olympics in Sydney, in this Saturday, September 16, 2000, file photo. Five-time Olympic champion Ian Thorpe has quit competitive swimming at the age of 24. "As of 2.53 on Sunday afternoon I decided I would not be swimming the world championships," Thorpe told a news conference Tuesday November 21, 2006. (AP Photo/David Longstreath, FILE)