I would like to recommend this site to all – http://www.ted.com
TED stands for Technology, Entertainment, Design. This site has a lot of videos on the presentations given by world’s greatest thinkers or entrepreneurs or actually anyone whose great ideas has contributed to the society positively.
This is the link to their RSS feed: http://feeds2.feedburner.com/tedtalks_video
The videos here are indeed knowledgeable and inspiring. Some of the interesting ones I’ve seen so far are from Bill Gates on Malaria and Education
Ed Ulbrich on How Benjamin Button got his face in the movie Curious case of Benjamin Button
Pattie Maes on Sixth sense (a MIT media lab project, this is quite interesting one)
Evan Williams on listening to Twitter users