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Shawn Johnson, 16, Gymnastics

At 16, she is perhaps the best -gymnast in the world-- a compact, powerful package who is just as at home on the beam and bars as she is on the vault and floor events. "She doesn't know how good she is," says former Olympian Shannon Miller. Shawn Johnson always has an easy smile and confidence and rarely betrays the nervousness she says she feels at every competition. That anxiety gets expressed only through her poetry, which she scribbles in a journal that's always with her or which she texts on her cell phone. One of her goals for the Games is to honor her coach, Liang Qiao (known as Chow), a Beijing native and former Chinese gymnastics champion. "I want to show everyone in their country their hard work through me," she says of Chow's skills as a coach. She will likely show her country, too.

--By Alice Park