I love the idea of TED. “Ideas worth spreading”. Clips of the talks or presentations are available. They seem to be between 5 – 20 minutes long. They vary quite a bit in topics from how ants organise their nests to how we can defeat ageing.

You can browse topics like Why we age and how we can avoid it. or A surprising idea for solving Climate Change, or you can browse by speakers, such as Steven Pinker and Larry Lessig.

Some very interesting talks by very smart people with engaging ideas if you’ve got the time.