The talks are held in Monterrey California and only 1,000 people can attend the live sessions. I first heard about this from David Pogue's Tech Tuesday column, when he was an attendee (he gave a shorter 3 minute "in-between" talk). The rest of the talks run about 18 minutes and draw from a varied range of speakers from all different fields. By the way, if you want to attend, it's $6,000 a ticket. If you are invited to talk, you get a free pass.
Online, head to ted.com/tedtalks. However I'm streaming it down via iTunes as a podcast. Head to Higher Education (show all), then TEDtalks.