Like documentaries? Like free documentaries even more? Then check out snagfilms.com which has more than 600 full-length selections. Popular choices include Super Size Me, by temporary fast-food junkie Morgan Spurlock, and Air Force One, an inside look at the President's plane.
Films are organized by title and topic -- and the site allows you to "snag" them and place them on your blog or Facebook page to share with friends.