If you have ever watched or been a fan of public television, you will know about WGBH  out of Boston. They brought Nova, Masterpiece Theatre (now just Masterpiece, Frontline, Antiques Roadshow, Curious George, Mystery and Julia Child to our TVs. Now you can watch or listen to an amazing collection of clips from their archives via their Open Vault project . Register for an account (it's free) and jump in. As they describe it:
[Open Vault] ... provide[s] online access to unique and historically important content produced by the public television and radio station WGBH. The ever-expanding site contains video, audio, images, searchable transcripts, and resource management tools, all of which are available for individual and classroom learning.
Thanks to Roy Tennant's Digital Libraries blog  for the tip!