http://www.audible.com
2. Audio Book Club
http://www.audiobookclub.com
3. MediaBay
http://www.mediabay.com
4. Voquette
http://www.voquette.com
5. AudioHighway
http://www.audiohighway.com
6. MP3Lit.com
http://www.mp3lit.com
7. Audio Book Company
http://www.audiobookco.com
8. Books On Tape
http://www.booksontape.com
9. Audiobooks.Com
http://www.audiobooks.com
10. Talking Book World
http://www.talkingbooks.com