TED talks bring some of the world best thinkers and doers together to share "Ideas worth spreading". Along with its once a year conferences in California and Oxford, TED affiliated events are now held around the world and many talks are put online for all to see.
Here's Rob Hopkins talking about the transition to a world without oil at TEDglobal in Oxford last year.
There are lots of other great TED talks available on the website, many along the Technology, Entertainment, Design subject areas but increasingly others too, such as A Greener Future? I'll be posting some more interesting talks in the near future.