Zac Efron - Teen Vogue Young Hollywood Party 2008

Zac Efron plays Mr. Cool at the 2008 Teen Vogue Young Hollywood Party on Thursday in Los Angeles.

The 20-year-old High School Musical heartthrob, who popped his jacket collar a lot on the red carpet, attended the event on the rooftop of The Los Angeles County Museum of Art with on-and-off-screen girlfriend Vanessa Hudgens.

Zac was Teen Vogue‘s cover boy for their October 2008 issue. The month before, Vanessa graced the cover of the teen mag.

15+ pictures inside of Zac Efron @ the 2008 Teen Vogue Young Hollywood Party…