I've never been an overly huge fan of audiobooks. If you want to look at a particular passage more closely, you have to rewind or go back to the previous section, and it's much more cumbersome than simply making your eyes scan up a few lines. And no matter how good of a reader the narrator is, for me, the dialogue always sounds better in my own mind.
That aside, like podcasts, I can understand why many people think they are superneat. Maybe after I get my MP3 player, I'll end up listening to them more. I did come across several books on NetLibrary that I wouldn't mind reading at some point.