Hamish said:Nah I mean so that I can rename the actual files without iTunes messing up my folder structure e.g.
fdsf_01.mp3 becomes 01 - artist - track.mp3
iTunes does that though. If you change all the tags (using Command-I to bring up the dialog), you can change your tags that way. Then once you are done, choose the "Reconsolidate Library" option from one of the menus (I forget which one), which basically rebuilds everything, and names files and directories according to the Tags. Of course, it's not customisable, but it should get pretty close to a sensible structure.
I used iEatBrainz to sort out a lot of my untagged music first, and then I fine tuned it manually afterwards. It looks like though that iEatBrainz is not compliant with iTunes7 (only 6).