TED is a nonprofit devoted to Ideas Worth Spreading. They hold two annual conferences at which some of the world’s top thinkers give talks. These TEDTalks are videotaped and shared for free on the web. There’s more than 1,000 TEDTalks available, and I highly recommend you check out the site if you’ve never done so.
I ran across this 3min video below last night and thought it nicely captured the concept of The Primal Challenge: