I'm not even sure how I found this - but you need to visit www.ted.com
According to their site: "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). "
They have videotaped these conferences over the years and the speakers are amazing and include everyone from Isabel Allende to Peter Gabriel to Jane Goodall. You can even download the videos as mp3 audiofiles.
I have listened to about 10 of them and I have particularly enjoyed Jill Bolte Taylor video - she is a scientist that studies the brain and one day woke up and slowly realized she was having massive stroke.