Pictures of Stephanie Pratt in a Bikini on her 24th Birthday at TAO Beach in Las Vegas 2010-04-13 14:30:00

Stephanie Pratt spent her 24th birthday at TAO Beach in Las Vegas on Sunday after partying with friends at Lavo the night before. She celebrated the day poolside in a tiny blue bikini between posing for pictures with friends and fans and digging into her beach-themed birthday cake. Stephanie's sister-in-law and The Hills costar Heidi Montag got a lot of attention for her bikini-filled weekend in Vegas, but the two apparently didn't cross paths in Sin City. Click through to see the highlights from Stephanie's bikini birthday!