A 55-minute video on Drupal by Angie Byron, "webchick," worth watching. Angie:
By popular demand, here are the slides from the Google Tech Talk I gave with Geoff Butterfield of the George Lucas Educational Foundation back in October. This talk consists of an overview of Drupal, who uses it, how it works, and what some of its killer modules are, and then specifics about how it's implemented in the site Edutopia.org.
Link: http://webchick.net/presentations/implementing-drupal-google