Since 2004, Rob Dyer (founder of Skate4Cancer) has been doing cross country skateboarding trips to raise awareness for Cancer. He's done this multiple times, the first one going from Newmarket, Ontario to LA, California. Here's the wikipedia article about him (and his foundation)
http://en.wikipedia.org/wiki/Skate4Cancer
Here's the page for the documentary about his trips: http://dreamlovecure.org/