From the official website: "TED stands for Technology, Entertainment, Design. It started out (in 1984) as a conference bringing together people from those three worlds. Since then its scope has become ever broader. The annual conference now brings together the world's most fascinating thinkers and doers, who are challenged to give the talk of their lives (in 18 minutes). "

You really should check TEDtalk (YouTube channel) but here's my fav list so far...

Tim Berners-Lee: The next Web of open, linked data
http://www.youtube.com/watch?v=OM6XIICm_qo&feature=channel_page

Kevin Kelly: Predicting the next 5,000 days of the web
http://www.youtube.com/watch?v=yDYCf4ONh5M&feature=channel_page

Johnny Lee: Wii Remote hacks
http://www.youtube.com/watch?v=QgKCrGvShZs&feature=channel_page

Sergey Brin and Larry Page: Inside the Google machine
http://www.youtube.com/watch?v=2FSE3TNFkJQ&feature=channel_page

Jimmy Wales: How a ragtag band created Wikipedia
http://www.youtube.com/watch?v=WQR0gx0QBZ4&feature=channel_page

Charles Leadbeater: The rise of the amateur professional
http://www.youtube.com/watch?v=W7raJeMpyM0&feature=channel_page

Howard Rheingold: Way-new collaboration
http://www.youtube.com/watch?v=d5s3Z0iesRM&feature=channel_page

Larry Lessig: How creativity is being strangled by the law
http://www.youtube.com/watch?v=7Q25-S7jzgs&feature=channel_page

Yochai Benkler: Open-source economics:  collaborative projects like Wikipedia and Linux represent the next stage of human organization
http://www.youtube.com/watch?v=NgYE75gkzkM

Brewster Kahle: A digital library, free to the world
http://www.youtube.com/watch?v=pXoHC2D15hM&feature=channel_page

Nicholas Negroponte: The vision behind One Laptop Per Child
http://www.youtube.com/watch?v=W5ySOqtxhbw&feature=channel_page

Richard Baraniuk: Goodbye, textbooks; hello, open-source learning
http://www.youtube.com/watch?v=RRymi-lFHpE&feature=channel_page

Sugata Mitra: Can kids teach themselves?
http://www.youtube.com/watch?v=xRb7_ffl2D0&feature=channel_page

Dave Eggers: 2008 TED Prize wish: Once Upon a School
http://www.youtube.com/watch?v=FaSF1gPBKrA&feature=channel_page

Sir Ken Robinson: Do schools kill creativity?
http://www.youtube.com/watch?v=iG9CE55wbtY&feature=channel_page

Philippe Starck: Why design?
http://www.youtube.com/watch?v=Z4PwHD7XKj0&feature=channel_page

Stefan Sagmeister: Yes, design can make you happy
http://www.youtube.com/watch?v=eZp-H9g_jeY&feature=channel_page

John Maeda: Simplicity patterns
http://www.youtube.com/watch?v=xHsXfmHaBUo&feature=channel_page

John Maeda: My journey in design, from tofu to RISD
http://www.youtube.com/watch?v=uNYMw9O2bu4&feature=channel

Dan Ariely: Why we think it's OK to cheat and steal (sometimes)
http://www.youtube.com/watch?v=nUdsTizSxSI&feature=channel_page

Jill Tarter: Why the search for alien intelligence matters
http://www.youtube.com/watch?v=EszGIvRdgTE&feature=channel_page