Set the Plays ("Play Count" before iTunes v9.2) of the selected tracks to a user-entered number (they will all be set to the same number). If this number is 0 then the Last Played date of each track will be erased. (iTunes has the ability to "Reset Plays" to 0 from a track's contextual menu.)
Also see New Last Played Date and Add or Subtract Play Count.
Display, create text file listing info of dead tracks
Convert or import tracks with any encoder on the fly
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags
Re-associate batch of dead tracks with files from selected folder
Enter text for the selected tracks' Long Description tag
Remove iTunes tracks disassociated from files