Famous For: Though she got her first taste of Hollywood stardom with Mean Girls, in reality Rachel McAdams is anything but. Quite the contrary; the Canadian-born actress, star of such hits as The Notebook, Wedding Crashers, The Time Traveler's Wife, and Sherlock Holmes, is smart, sweet, and seriously down-to-earth. When not on set, the brainy beauty eschews Hollywood excess in favor of a quiet, low-key life in Toronto – no wonder she’s sometimes known as the thinking man's Hollywood crush.

Cause Célèbre: Though she prefers to stay way from paparazzi hotzones, McAdams isn't afraid to take it public when it comes to her commitment to the environment. Together with two friends, she founded green is sexy, a website devoted to sharing information and advice on green living. The site features product recommendations, profiles of eco-champions, recipes, links, and lots of easily-digestible tips to help readers green their lives. So even if you aren't ready to do a total green renovation of your home, commit full time to your bike, or forego air conditioning – all of which McAdams herself has done – you can find plenty of practical tips to help you make the shift to a greener lifestyle, and look good doing it. Because as McAdams proves, going green is undeniably sexy!

Green Link: www.greenissexy.org