This script will apply user-entered text to the "Category" tag of each of the selected tracks. iTunes 5 or better.
(Note: In order to launch this PowerPC-era script on an Intel machine, it must first be opened and then saved using AppleScript Editor, which is located in your /Applications/Utilities/ folder. More information is here.)
Use special track to stop iTunes, cue next track
Applet assists with swapping, copying, appending data between track tags
List tracks not assigned to playlists
Apply selected CD's CD Text to its disc and track tags
Advance or rewind the currently playing track an entered number of seconds
Locates .m3u files and allows you to select which to delete