OS X 10.8 or later. This script will look for an image file in the parent folder of each selected track's file--presumably its Album folder in which you have previously placed an image file of some sort--and apply the data from that image file as artwork for the track.
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Perform tasks on a batch of playlists; rename, delete, duplicate, merge, more
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Capitalize the first letter of each word in selected track names
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Use tag data to formulate new file name for selected tracks' files
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Export files of tracks in two or more playlists to single folder
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Remove iTunes tracks disassociated from files
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Set choice of various number tags of selected tracks incrementally