Last week we linked to Listening to Words, which collects lectures from many sources. But one of the best sources of lectures on the web is the TED conference, which attracts top-notch speaking talent.

Best bets: William McDonough on Cradle to Cradle Design, Ze Frank being funny, Dr. Jane Goodall on her research.

Fun tip: when viewing the list of talks, click "visualization" in the left navigation.

Thanks to commenter Olivier for the tip!