Zac Efron: Busted with a Six Pack 2/11/2009 12:50 PM PT Zac Efron went for a topless solo hike in the Hollywood Hills on Tuesday. The "High School Musical" star has graduated into quite the buff 21-year-old man-boy. See Also Zac Efron: Damn I Look GoodZac Efron: Armed & Fabulous Share on Facebook Share on X Zac Efron Hot Bodies Beauty Paparazzi Photo