After much running around and jumping up and down, trying to convert .aa to .mp3 so I can listen to Audible books, I found a VERY SIMPLE SOLUTION. While in London Drugs in Regina yesterday, I checked their stock of MP3 players. I ended up buying an RCA LYRA TC1101 1gb player. It has a slot for a microSD card. There was also a 2gb model for another $20. This one I bought was about $45. It plays .aa files!! The only trouble I am having is when I transfer a normal .mp3 file to the card, the player wants to only recognize the file as "music" and won't let the file play from the "Audiobooks" menu. The "music" menu plays the file in random choice unless you actually scroll down to whichever chapter or "track" you want. I'm not sure what it would do once it plays the selected chapter out. I haven't got that far yet. The salesman was sharp enough to actually look at the back of the box and found that the player actually plays Audible files, thus it will resume where you shut it off. Some other MP3 players will do that, but the packaging and instructions don't say so. I have two CREATIVE MuVo V100's and a V200 that will. Hope this helps people who have been put off Audible books.