I came across a list of 15 podcasts that will "make you smarter."  Kinda funny that two of them were already on my personal list.  I think I'll check out a couple more of them.  Here's the list if you want to try them too.

I've got to say that I REALLY like the University of California, Berkeley podcasts on American history, and most of the How Stuff Work podcasts.  Granted, I would have ended up reading books or websurfing to get the info instead, but it made my car ride more productive and even made work more interesting sometimes.

If you have an mp3 player, Zune, or iPod, you owe it to yourself to check out podcasts.