Michael Phelps won a gold medal inhis final individual swimming race in his Olympic career Friday in London. Phelps won the 100m butterfly. He now has 17 career gold medals, three in the London games and a record 21 overall. He is retiring after these games. Phelpos likely will get another gold Saturday night in his final Olympic event-- he is a member of the heavily favored 4x100 m medley relay team.