Sure, these Hollywood hotties and rock stars sometimes hop fuel-guzzling charter jets and lead planet-killing concert tours, but their hearts are in the right place. Here are some leaders of the celebrity green movement.
Jessica Biel joined Emile Hirsch and others in climbing Africa's tallest peak, Mt. Kilimanjaro, to raise awareness of the global water crisis in 2010. She strolls past the paparazzi toting reusable shopping bags and appeared in a carpooling PSA with the dorkiest -- and luckiest -- commuter ever.