Angelina Jolie

Cause: Helping refugees, disaster victims, orphans. Jolie, 31, began work with the U.N. High Commissioner for Refugees in Sierra Leone in 2001, the year she became a goodwill ambassador. She has put her time, influence and millions of dollars into helping people in Sudan, Chad and Thailand.

Impact: She donates one-third of her income to charity, and her three adopted children—Maddox, Zahara and Pax—are examples of her continuing commitment to helping those in need.