OS X 10.8 and later. This script will export then re-import the artwork data of the selected tracks.
Note: This script may not be able to handle processing more than about an album's worth of tracks per launch due to the way iTunes manages graphics data.
Also Note: (August 2014) Not sure what the issue is but results may be inconsistent with modern versions of iTunes.
Remove iTunes tracks disassociated from files
Locates pairs of track entries pointing to the same file
Create a Ringtone track from a selected track
Convert selected tracks and replace them with converted versions
Droplet/applet adds files, creates playlists based on artist-album or folder name
Change the iTunes "done" chime to a System sound, no sound, or your choice of an AIFF sound file