I second the motion on bamboozled.  Among many interesting elements, the
montage of film and tv images that ridicule blacks is stunning.  I use it in
my film history course as a supplement to the unit on Grifftith's _Birth of
a Nation_ and Micheaux's _Within Our Gates_.  If you've not seen _Network_,
watching that first helps to frame the issue of media influence in

Though I don't agree with Lenny Bruce's criticism of Twain's portrayal of
blacks and use of dialect, his bit on "gwyne" is also very provocative and
worth a listen.