I've really been getting into the podcast feature on iTunes lately. You can browse a huge library of free podcasts, pick the ones you want, and iTunes will automatically download them, so they're ready to go whenever you want to listen.
I've got a few of my favorite news shows from NPR, but I also recently subscribed to the Ricky Gervais podcast. If you aren't familiar with Gervais, he's the guy who created and starred in the original British version of 'The Office.' And now, together with the co-writer and producer from that show, he's got a series of half-hour radio/podcast shows where they basically talk about nothing at all - and its hilarious.
One of their weekly features on the show is 'Monkey News'. Click here for a little taste.