Tech Talk: Human Computation
Cool Tech Talk: Luis von Ahn from Carnegie Mellon talks about Human Computation.
Other interesting ones from my list:
Linden Labs on Second Life
Gregor Kiczales on Aspect-Oriented Programming
Jared Spool on Branding
Jen Fitzpatrick on Google's User Experience (a lighter-weight talk)
Alan Karp on Virus-Safe Computing
William Pugh on Static Analysis for Defect Detection (aka FindBugs)
Now that you're caught up, I'll drop them one at a time so I don't blow your day.