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.)
Make a text file listing Albums that have some/no tracks with artwork
Change file type to make selected AACs bookmarkable
Update subscriptions which have expired by virtue of being ignored for five or more days
Perform search-and-replace on text in your choice of tags
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags
Reset selected tracks' bookmark position to their Start Time