OS X 10.8 or later only. This script will export the artwork of the selected tracks (or the tracks in a selected playlist) as an image file to the folder which contains each selected track's file--presumably the track's Album folder--or a single user-selected folder. If multiple album tracks are selected, the script will make sure only one artwork file per Album is exported.
Also see Save Album Art as folder.jpg.
This Preferences pane for the script remembers your settings between uses.
Exports and then re-imports selected tracks' artwork
Export album artwork as folder.jpg to Album folder
Edit a selection of iTunes tracks' tags in single window
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags
Add or subtract a user-entered number from each selected track's Plays
Batch set new Last Played/Last Skipped of selected tracks