Around the world, film archives take particular pride in preserving rare and valuable feature films. Forgotten classics by directors such as John Ford, Ernst Lubitsch, and Josef von Sternberg might be lost to us forever if not for the wise acquisitions of an archive. Yet for every feature reel of Citizen Kane or Battleship Potemkin there are thousands of short reels of filmsmall treasures of unusual or offbeat material. A recent review of Harvard Film Archive holdings has turned up such unique short subjects as German animated appliance ads, silent-era films on personal hygiene, and shorts extolling the virtues of Guinness. Much of this material is passed over in favor of preserving the full-length films, but very short films have a unique charm and also deserve to be seen. Tonights screening is a sampler of shorts, commercials, trailers, and avant-garde material, each of which clocks in at three minutes or less.