A month or two back, I heard about this offer of free daily video clips from Arbeats. (http://www.artbeats.com/)
A lot of the clips are of so-so quality — interlaced video with evident breaks in the primary subject matter. But some of it is first-rate. And some of it is footage you could not get on your own without big money (or a substantial knowledge of 2.5D and some really good photos).
I heard they were going to do this for a year (till probably around Mar 1, 2011), but their site suggests they have no plans to discontinue the offer, so it’s a great way to amass a library of footage — especially for personal projects, tests, or pre-vis.