This script converts the files of the selected tracks in iTunes using an encoder of your choice on-the-fly (restoring your Preferences-set encoder afterwards). The newly converted files are then moved to a new location of your choice, and their tracks removed from iTunes.
OS X 10.6.8 or better.
Also see ConvExp to Album Folders.
Exports and then re-imports selected tracks' artwork
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags
Convert selected tracks and export the converted files to a new folder
Create a playlist for each entry of a specified tag
Copy files of selected tracks to playlist-named folder
Deletes the lyrics of every track in the Music playlist