I really enjoy the free TED talks; If you haven't already discovered them yet, go to www.ted.com and take your pick from more than 900 talks on topics as diverse as poetry, primates, language and leadership. There's a free iPhone app too.

I really enjoyed listening to Julian Treasure speaking about - appropriately enough - listening:

"In our louder and louder world, says sound expert Julian Treasure, "We are losing our listening." In this short, fascinating talk, Treasure shares five ways to re-tune your ears for conscious listening -- to other people and the world around you."