UbuWeb is billing itself as “The YouTube of the Avant-Garde,” having converted all of its rare and out-of-print film and video holdings to on-demand streaming formats: “We offer over 300 films & videos from artists such as Marcel Duchamp, Vito Acconci, Pipilotti Rist, Jean Genet, The Cinema of Transgression, Richard Foreman, Terayama Shuji, Paul McCarthy Jack Smith, Carolee Schneeman, John Lennon and hundreds more—of course all free of charge.” You could start with some Peter Greenaway films of “Four American Composers,” or—better yet—with Robert Smithson’s excellent Hotel Palenque.