The Musicmaker Relief Foundation is now on Youtube and has 23 videos up of southern blues musicians - some known among bluesmen (and women) and some not. These are for the most part 'field' recordings and videos. A treasure.

Maybe I should have added this to the Youtube thread, but these videos, documenting these old and soon to be gone people and their music is too significant, IMHO.
http://www.youtube.com/musicmakerfoundation