Britney Spears spent her first weekend as a new divorcee in Las Vegas, dining with close friends. The fallen pop superstar finalized her divorce from rapper Kevin Federline last week and took off to Sin City for a low-key weekend. The post-rehab Spears dined at Tao Asian Bistro on Saturday night with two female friends, and made it clear her partying days are over -- even in Las Vegas. A fellow diner who spotted the party says, "Britney was dressed casual, wearing a light coat, hat and blonde wig. She and her friends ate vegetable dumplings, hot edamame, a California roll, and they split a wasabi filet. "This wasn't a wild night out. Britney drank Pepsi and the girls were in and out in about an hour. Britney seemed very happy."