Here's what I've done:
I set up a folder heirarchy with the top level named by the genre (Rock, Pop, Alternative, etc). Within each of those folders is a folder for each artist, and in each artist folder are folders for each album, then the tracks are named with the track number (01,02,etc) and the song title. There are still some names that are longer than 31 characters, but most are still recognizable. Using this, I can tell the genre, artist, album, and song title from the folder path. That's the best way I've come up with. Besides, using labels, you only have 7 categories.