Science for the Car Ride?

qaffle asks: "Being a commuting college student I've been putting many hours on the road recently and have gotten sick of the repetition of regular radio and music in general. I've been trying to listen to talk radio but all that is ever talked about is sports and I can only listen to Bears updates for so long. I'm curious if anyone knows of any sites online where I can find good science, computer related, or physics audio discussions online that I could listen to on the drive. This should give me a good variety and the ability to listen to something interesting during mid-late morning and early afternoon drives."