The Chicago Underground Film Festival
The festival for the defiantly independent filmmaker. CUFF presents films and videos that dissent radically in form, technique or content.
http://www.cuff.org/

The Images Festival of Independent Film & Video
Toronto's annual spring celebration of independent and experimental film and video, featuring ten days of screenings, installations, performances and symposia.
http://www.imagesfestival.com

Antimatter Festival of Underground Short Film and Video
An annual festival held at Open Space Arts Centre Victoria, BC, Canada. Also includes Foreign Matter -- showcasing works from around the globe.
http://www.antimatter.ws/

eKsperimEnto Seattle Filipino Film and Video Festival
site for eKsperim[E]nto, a film and video fest featuring experimental shorts by Filipinos, Asians and others.
http://www.geocities.com/eksperimento/

Free Form Film Festival
Traveling collection of film and video works.
http://www.freeformfilm.org

Portland Underground Film Festival
Featuring independent underground films and videos.
http://www.clintonsttheater.com/puff/

Courtisane
Annual festival for experimental and alternative short film, video and new media in Ghent - Belgium.
http://www.courtisane.be/

New York Film Festival: Views From The Avant Garde
Views from the Avant Garde is curated by Mark McElhatten and Gavin Smith. This yearly event is part of the New York Film Festival at the Film Society of Lincoln Center.
http://www.filmlinc.com/wrt/programs/avantgarde05.htm