Ed Begley, Jr.
The series has featured various celebrities including Sting, Alicia Keys, David Duchovny, Ryan Seacrest, Simple Plan, Hoobastank, Simon Webbe, Desmond Tutu, Ian Thorpe, Jackie Joyner-Kersee, Bart Conner, Daryl Hannah, Gavin Newsom, Amy Smart, Ed Begley, Jr., Julia Butterfly Hill and more.