Chris Brown was persona non grata in Las Vegas over the weekend. Because he isn't yet 21, the singer was turned away from the Swagg bash at Tao Beach, where Jamie Foxx, Anna Paquin and Stephen Moyer, Busta Rhymes and Nelly partied. Brown was looking for a place to celebrate his 21st birthday, which is tomorrow, but hadn't found any clubs that would welcome him and his posse.