This page has been created in response to a question about video archives that could be useful for activists (and those who love them). We hope the list will grow and welcome suggestions and additions.
Paper Tiger Television: Founded in 1981. Their website has clear links to history, mission, staff, and funders pages. Its Links and Resources page includes alternative press, radio, and websites. A 12 page Paper Tiger Curriculum Vitae includes PPTV activities and articles about the organization back to 1985. Their Catalog can be viewed as a long list or searched by title words, description, year, or by any of 22 main categories.
Deep Dish TV: Started producing alternative TV in 1986. Its Catalogue lists many individual progams under each of the main series titles. It lists many other resources, including a main Links page.
There is a rich collection of moving images at the Internet Archive, which can be searched for relevant subject terms, and then those results can be narrowed by subject, for example search "radical" and limit to "newsandpublicaffairs" gets 14 items.
There is an excellent collection of sound and video from artistic and cultural avant-gardes on UbuWeb, many of which may be relevant. Try searching terms such as "situationist" etc.
RESEARCHING ALTERNATIVE MEDIA: At large academic libraries, try searches such as "alternative media" in databases such as Project Muse (81 hits in December 2007), or JSTOR (419 hits in December 2007). JSTOR is a very large full-text database, so very specific searches also work: "alternative television" gets 35 hits. Very large libraries will have Social Sciences Citation Index and Arts and Humanities Search. Using the ISI version of this, A&HSearch combined with SSCI got 9 hits for the phrase: "radical media" and 4 for "alternative video"
Video.google.com is especially useful for tracing obscure or very recent videos - especially if you know the names of people or places involved. Even a rough search will get interesting results. Search: radical site:edu to try to limit to university or college related videos, for example. But such an approach is extremely crude - it might get chemistry class videos on free radicals, etc.