Hi! I just got myself an 80GB Neuros II and am very happy with it so far. I am a Linux user and Linux compatibility as well as ogg support were high on my list of criteria when looking for an mp3 player.
To answer your question, you could also check out positron
http://www.xiph.org/positron/. This is a command line database manager written in Python. If you check out the docs you will find some useful data on the layout of the database in the developer's guide.
Hope this helps.