I don't think that this has been brought up here before but there is a very enjoyable 2007 documentary about John Cohen available to watch in its entirety at the Smithsonian Folkways site:
http://www.smithsonianchannel.com/sc/web/show/131378/play-on-john-a-life-in-musicRecommended, especially for banjo nerds. Film of Roscoe Holcomb, The New Lost City Ramblers, footage of Cohen playing with Bruce Molsky, Ray Alden, Rayna Gellert, Pete Seeger and others. Some footage of a very young Dylan goofing with the contents of his guitar case. It all reminded me of how many photos and films that I've seen were shot by Cohen as well.
The button to make the video full-screen is in the top left corner on the Smithsonian player, if you're looking for it for ages like I did.
