One of the podcasts I listen to (TWIT: This Week In Tech) has been advertising for http://audible.com . They are an audio book service.
If you go to http://audible.com/twit/ you can get a free audio book. You do have to sign up for the service with a credit card, but you have 14 days to cancel. I looked and there is a cearly marked "Cancel Service" button on the accounts page, so that should be easy to do. The service is $15.00/month if you keep it, but with that you get one "free" book/month plus lower prices on other books.
The selection is really huge. You can listen through your computer, or put the book on most popular mp3 players.
Yesterday I downloaded and started to listen to Dr. Laura's "The Proper Care and Feeding of Marriage".
I don't know if I'll cancel or try it a few months and listen to a few more books. I do know that I'm a better listener than reader.