Stars' New Year's Parties!

Toast 2010 with Christina Aguilera, Nicole & Joel, Lauren Conrad and more Hollywood dazzlers

LADIES NIGHT

Back in Hollywood, Lauren Conrad and her girls – Stephanie Pratt (left) and Lo Bosworth – partied at Beso, but at least one of them was feeling the effects New Year's Day: "My legs are so sore from dancing!" Pratt Tweeted.