Online Videos by Veoh.com
A guy named Figerola has recently been posting some rare and historic documentaries by Cuban director Nicolas Guillén Landrian. (Unfortunately they're on the advertising-plagued Veoh.com, but what can you do?)
"En un Barrio Viejo" is my favorite one, because of the great shots of Havana life c. 1964, and of course the wild afrocuban footage (mostly starting at about 6:40). That caiman on the head is pretty hard to forget. There's another film of his featuring Pello el Afrokán here.