9. Guo Jingjing

Diving
China
Age: 26

Guo Jingjing began her diving career a little late for an élite Chinese athlete: age 6. She managed to catch up, making her Olympic debut as a 14-year-old in Atlanta and winning two springboard golds in Athens. But Guo, now 26, and the other Chinese divers may have more catching up to do. In May she didn't even make the finals of a springboard event. It could be pre-Olympic jitters for one of a fleet of divers expected to sweep the medals. Maybe it's those outsize expectations that have made Guo a bit of a contrarian. When she dared spend time on endorsements after her Athens double, she was reprimanded by sports bureaucrats. And after she dismissed Canadian challenger Blythe Hartley as a "fatty," her coach had to apologize. "Guo Jingjing is just a child," he said. "She can't express herself perfectly." Except perhaps on a diving board.