Pot au feu
The infamous banned short film, directed by Robert Altman, that features people going about their day while smoking pot. Altman was an advocate of the drug and served on the board of directors of the National Organisation for the Reform of Marijuana Laws. Pot au Feu was shot for just $1000 over a couple of weekends in 1966, but was never officially released. Altman cameos during the chess scene.