I've listened to a couple and they're good for multitasking (if you can pull it off, there are times when I can't concentrate on a story and other things on the same time. Even if it's something easy like MMO grinding ) But for the most part though I've never had much of chance to listen to them because I very rarely have a commute that's over about five minutes.

There was some recent study done that showed that listening to an audiobook whilst driving was considerably more distracting than listening to music whilst driving so I'd tell everyone who does it to be a little extra cautious