Britney Spears greeted photographers with a big smile at LAX today on her way out of town. She's headed overseas, including a stop in Japan to keep promoting Circus, which opened at No. 1 in countries all around the world. After sending us all her holiday greeting with Sean Preston and Jayden James, the boys are back with their daddy while Brit keeps showing off her album. Britney is your overwhelming choice for Most Improved of 2008, and we're all rooting for that streak to keep up in 2009.