Randy Pausch gives his last lecture. The first embedded version below is a condensed version from the Oprah show (10:09). The version embedded below that is the full lecture given at Carnegie Mellon University (1:25:21, he starts talking at about the 8 minute, 28 second mark, although the introductions aren't bad either).
For folks in my district, they're blocked by the filter, so teachers use your overrides, students you'll have to view at home. It's worth your time.
Update 11-3-07: They've taken the video down off of YouTube. You can still watch it from this page on Oprah's site.