INTERACTIVITY: PEOPLE & Places:
Steve Wilson's Mother of all links
Also: http://www.stetson.edu/~mdemurga/interactive/links.html for people using sensors.
Artists, writings, clips...: http://www.ubu.com/
History, artists, writings, bios.... mediaartnet.org
Here are a few others (in progress - probably already all in Steve Wilson's page):
Bert Bongers (Builds a lot of interesting interfaces, including the latest incarnation of my lady's glove.)
Center for New Music and Audio Technologies (CNMAT)
Exploratorium in SF
Matt Heckert (he also has a lot of interesting links at http://www.mattheckert.com/SFAI_ap.html
Bernie Lubell