Yoga practitioner, supermodel, entrepreneur, mom, activist and author (whoa!) Turlington has been a spokesperson and poster child for antismoking campaigns, PETA and various humanitarian efforts. She is the creator of natural skincare line Sundari and uses eco-friendly, organic cosmetics such as those by Nude Skincare.

Aside from backing the Volvic 1L for 10L partnership, which helps provide clean water to people in Africa, Newton wears and encourages others to wear recycled clothing. After trading in her BMW X5 for a Toyota Prius, she launched a letter writing campaign to get fellow celebrities to ditch their SUVs for greener vehicles.

Actress, model and mom Valleta lives an eco-conscious life with her family and is actively committed to various causes, most notably Oceana's Stop Seafood Contamination campaign. She is one of many celebs featured in the Sundance Channel's "Ecoists," a series of short videos showcasing celebrities and their green causes.

EMA Missions in Music Award winner and environmental activist Morissette narrates several global warming documentaries including "Global Warming: The Signs and The Science" by PBS and "The Great Warming" with Keanu Reeves. She has spoken out against drilling in the Arctic National Wildlife Refuge and encouraged fans to learn about and become more involved in political issues involving energy. She also practices basic green habits like using solar panels to power her home, cutting down on air conditioning, turning lights off and recycling.

Grammy-winning Crow got busy publicizing her eco-friendly record in 2007. She promoted Stop Global Warming with founder and activist Laurie David, advocating "one square per restroom visit" in addition to raising environmental awareness by touring the country in a biodiesel-powered bus. Crow also threw an eco-friendly baby shower featured in InStyle magazine. (Find out how to throw one like it here.)