Britney Spears took the stage last night for her first live performance in the run up to Femme Fatale's release on Tuesday. She was in Las Vegas at the Palms's Rain nightclub for a secret show that included an introduction from special guest Pauly D, who first met Brit last year. Part of the evening was taped for an upcoming MTV special in honor of her new record, and she sang and danced to a variety of songs that you love like "Hold It Against Me" and "Till the World Ends." Around a thousand fans got to see Brit in action, and many were thrilled with what they saw. It seems Britney herself was pleased with the outcome, as she later tweeted, "OMFG it feels good to be on stage again!" She'll get to do it all tomorrow too, as she's scheduled to sing again in San Francisco.