CHRISTIAN PETERSEN—GETTY IMAGES

Kerri Walsh, 29, and Misty May Treanor, 31, Beach Volleyball

The greatest show on sand, Kerri Walsh and Misty May-Treanor are three-time world champs in beach volleyball, and defending Olympic gold medalists. Walsh is an outgoing, 6-ft. 3-in. kill machine, while the 5-ft 9-in. May-Treanor is known for her quiet intensity. May-Treanor is married to Florida Marlins catcher Matt Treanor. And as playing partners who have traveled the world together for the last eight years of course they can get on each other's nerves. "The thing that annoys me most is that she's the ultimate speed reader," says May-Treanor of Walsh. "How does she do that?" What's Walsh's biggest complaint about May-Treanor? "I want her to talk to me a little more," she says.

--By Sean Gregory