Pussycat Doll Nicole Scherzinger celebrated her 33rd birthday this weekend in Las Vegas. She spent Friday at Marquee Dayclub (Cosmopoloitan) and later dined at Lavo (Palazzo). Scherzinger was at Marquee again Saturday, this time in a cabana with friends who surprised her with a cake. That night she headed to Tao were she dined, and danced in VIP. (Photos courtesy of Denise Truscello/ WireImage).