The Girls Next Door star suits up in her two-piece to lead the world's largest bikini parade in Las Vegas. Plus: Gretchen & Slade, Ellen Pompeo, Pete & Ashlee and more

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TRAIN SPOTTING

Low-key traveler Owen Wilson arrives by train into Washington, D.C., Thursday for the premiere of his new comedy Night at the Museum 2: Battle of the Smithsonian. The actor reprises his cowboy role in the comedy, which opens May 22.