Thanks for the heads up. I'm a huge fan of In Our Time, which for the uninitiated is a radio programme which invites experts to discuss topics chosen from virtually any field of knowledge from culture and history to philosophy and science. They've improved access to their huge archive on the website so that you can listen to any of the past broadcasts on such topics as the Library at Nineveh, John Wyclif, Antarctica, and Language and the mind. I recommend checking them out.

Thanks for the tipoff John. Here's a link to the show in podcast format:
http://www.bbc.co.uk/podcasts/series/iot