The annual Learning Without Frontiers event in London - run by the indefatigable Graham Brown-Martin, sees a string of great inputs (this year including Resnick, Wolfram, Chomsky...even the wonderful Ellen MacAurthur!) in short usually 20 minute inputs that give it a very pact feel, with a gallery of more conversational bits - this year hosted in inflatable igloos.
This was my 20 minute's worth of input and I'm quite pleased with the pace and content.
This is it on YouTube: http://www.youtube.com/lwf#p/u/1/_hrvli_wCT0
But it is also available direct from the LWF site: