Great Wired News piece on the Stockstock film-festival, where footage from the Prelinger Archive of ephemeral films is used as the raw material for a festival's worth of short movies.
Festival operators pore over films in the online Prelinger Archives and choose a mishmash of films that are then combined and pared down to a 40-minute tape. Entrants must create a short film, limited to three minutes, using the footage provided. They can manipulate the films however they like and add dialogue, titles and music. All that's required is a computer with video-editing software and the $20 entry fee.