I love listening to podcasts while knitting, it helps pass the time. I have an iPod and get my podcasts on Itunes. I subscribe to a few so that they are downloaded automatically when they come out. Podcasts I listen to regularly are:
PotterCast (Harry Potter podcast)
MuggleCast (another HP podcast)
deos shadow (Pagan podcast)
Lime and Violet (just started listening to this one, a knitting podcast, really good!)
I've also got a couple meditation podcasts downloaded to help me concentrate while meditating. I've also in the past downloaded LetsKnit2gether which is a video podcast about knitting, also neat, but can't watch it unless you have a video iPod.
Itunes has a ton of different podcasts to choose from, you just go to "Podcasts" in the Itunes store and then you can browse in whatever topic you are interested in.