Hayden celebrated her birthday with 75 of her closest friends at the LG House in Malibu last night. Hayden is 18 now and you know what that means - voting! In fact, she's even getting involved in Declare Yourself, a campaign that urges 18 year-olds to register and vote in the November election. Of course, becoming a legal adult isn't all business for Hayden. When Letterman asked her about celebrating, she said, "We're going to have a big party. I think it will be my biggest party yet." Hopefully Hayden didn't regress to her 16 year old party with Paris ways because we like the girl she is growing up to be. Apparently at her big bash there was so much cake even the paparazzi got to enjoy some. All that cake would go great with her newest photo op - a Got Milk ad with her costar Masi Oka!
Lots more of Hayden all smiles for her big day so