TED

http://www.ted.com/tedtalks/

The talks from this annual conference are online and also available on iTunes. Definitely worth checking out!

My favorites:
Barry Schwartz - choices make us less happy
Steven Levitt - freakonomics and Chicago gangs
David Deutsch - on being improbable
Jeff Han - awesome touchscreen control -- now part of the iPhone
David Pogue - humorous musical takes (a la Tom Lehrer) on software
Tony Robbins - inspirational speaker surprisingly inspirational
Hans Rosling - making demographic statistics come alive

UPDATE: Here is David Pogue's (unaired!) video on the conference:
http://www.cbsnews.com/sections/i_video/main500251.shtml?id=2404760n