Stacy Keibler and Michael Phelps kicked off New Year's Eve celebrations a little early with a game of beer pong.Keibler, 33, and the Olympic gold medalist, 27, are ringing in the holiday down in Cabo San Lucas, Mexico, along with Keibler's man George Clooney. The gorgeous beauty tweeted a photo of herself posing with her beer pong partner, writing, "Dominating.