I was the last person in my family (and probably the developed world) to get an iPod -- though I still occassionally sneak some quality time with Old Faithful, my Sony Walkman, which is literally held together by rubber bands.
I have found a few top-notch podcasts, including the Daily Audio Bible, which will take me through the Bible in one year. This one runs about 20-25 minutes a day, with daily readings in the OT, NT, Psalms, and Proverbs.
I know that the Podcasting world is vast, and I will never "stumble on" to all of the good ones. I'm not looking for sermons or church services, but rather Christians discussing theology, culture, church history, stuff like that.