I, too, am a podcast addict. I prefer not to put myself into recovery just yet, thanks. I found that they are fabulous to listen to when knitting. I couldn't knit and read at the same time (at least not until kindle/iPad) and podcasts were fun while knitting.
Here are my favs:
This American life
Wait, Wait, Don't Tell Me
Astronomy cast
Classic Tales by BJ Harrison
Radio Lab
The Moth
