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.
Perform search-and-replace on text in your choice of tags
Attach files of selected tracks to a Mail message
Copy files of selected tracks to playlist-named folder
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags
Remove iTunes tracks disassociated from files
Export files of selected tracks into Album folders