A place to start would be librivox.org. I have only listened to a couple of samples, but they seem to be okay. They are a volunteer based organization trying to get all the classics (public domain books) into audio, if you have a desire you can offer to read and post files. They have a fairly large library available and you can get them sent as podcasts as well. When I finish with my current "read" I plan on digging a little deeper through thier catalog.
Oh that's cool! Thanks!