Like many people — at least those who aren’t compulsive gamblers — Bradley Cooper can take about 48 hours of Las Vegas before feeling the itch to leave.But Vegas is a big reason Cooper can lay claim to ShoWest’s 2009 Comedy Star of the Year award. The “Nip/Tuck” thesp spent spent a month living at Caesars Palace last fall while filming “The Hangover,” a movie Cooper describes as a cross between “Bachelor Party” and “Memento.” Warner Bros. obviously thinks the film is a good bet, as it’s releasing the movie in a prime June 5 slot. “It’s Vegas during the day, and you don’t ever want to see Vegas during the day,” Cooper says of the film, which has three would-be groomsmen woozily retracing their steps the morning after a bachelor-party blowout. When they wake up, they discover a tiger in the bathtub and a baby in the closet, but no sign of the groom. “Shooting in Vegas for a month was absolutely perfect for the vibe,” he adds. “Vegas really messes with your chemistry. Living there that long was like being on some long, weird acid trip.” “The Hangover” is one of three movies this year (possibly four if Paramount releases “Case 39″) to prominently feature Cooper. The other two are “All About Steve” and “New York, I Love You.” In fall comedy “Steve,” he plays the title character opposite Sandra Bullock, a crossword-puzzle writer obsessed with Cooper’s cameraman character. “He thinks she’s stalking him, but she’s really not,” says Cooper, who was part of the “He’s Just Not Into You” ensemble, a film that has grossed a healthy $91 million so far following its February release. “Personally, I’d be OK with Sandy stalking me. That would be a stalking that would end very quickly.” Cooper is in a segment of “New York, ” a collection of 12 short films from the producers of “Paris, je t’aime.” “There’s no dialogue … it’s all about behavior, with voiceover,” Cooper says of the Hughes brothers-directed segment, which co-stars Drea de Matteo. As for returning to Vegas to pick up his ShoWest honor, Cooper couldn’t be happier, because he sees the award as a sign of Warner Bros.’ faith in “The Hangover.” “Plus, I don’t have to stay for a month this time,” Cooper adds with a laugh.