Garageband export - urgent!

I've made an audiobook of around 7 hours and split it into chapters. When I export it using aac all is well. I can put it on my ipod and listen through the book, skipping chapters when I want to.

I'm aware though that some people don't use Itunes and Ipods, so want to export as mp3 too. This just creates a huge file though. Is there an easy way to split the chapters into separate mp3 files?

Sorry for the "urgent!" tag, but I need this asap to hit a deadline

Thanks

Bump.

Nobody any ideas?

I'm getting desperate (

1. Download Amadeus Pro ($40) or Audacity (free)
2. Open the MP3 in either of those programs and mark the individual tracks with markers.
3. Export. This will split each track as a separate file.

Now you know why audiobooks are generally in MP4 format, which natively supports chaptering.