Bernard--As long as it's MP3 and not WMA, the reader will play it.
If you think you'll be listening to a lot of audio books though, I recommend buying a dedicated mp3 player. One thing that's important for listening to audio books is that the mp3 have a resume feature. That means if you stop listening in the middle of a file, the player will picked up where you left off. Not very fun to try and find your place in the middle of a long audio file each time you start listening. I'm not sure if the Reader would do this or not.
dordale
