This script checks your entire iTunes library for missing and presumed dead tracks--those tracks that iTunes is unable to associate with a file and which are listed in iTunes with a "!"--and can create a text file listing these tracks by alleged File Path (if available), Song Name, Artist and Album, which you can view using TextEdit.
OS X 10.6 and later only. Universal version for PowerPC machines available at the link below in the "Info" section.
Also see Music Folder Files Not Added
To find and delete dead tracks see Super Remove Dead Tracks.
See the video on YouTube.
iTunes can't find the files pointed to by the Location property of these track entries.
Exports and then re-imports selected tracks' artwork
Set new Last Played/Last Skipped of selected tracks
Create a PDF booklet containing info from the selected tracks
Renumber order of selected tracks
Update subscriptions which have expired by virtue of being ignored for five or more days
Remove iTunes tracks disassociated from files