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2011 VH1 Do Something Awards - Show

HOLLYWOOD, CA - AUGUST 14: Singer Demi Lovato perform onstage during the 2011 VH1 Do Something Awards at the Hollywood Palladium on August 14, 2011 in Hollywood, California. (Photo by Kevin Winter/Getty Images)

Slideshow: Young stars who look mature

They're teenagers? Really? Forget overspending at the mall, exceeding cell phone minutes, and staying out past curfew—today's famous teens are living large and dressing the part.