OS X 10.8 or later. iTunes only allows one playlist to be selected at a time. This applet can perform common useful tasks on a multiple selection of playlists: rename (add text, remove text, search and replace text), duplicate, delete, export, merge.
Tools in the Rename tab operate on the selected playlists' names
Remove selected tracks and Trash or delete their files
Convert selected tracks and replace them with converted versions
Set the Plays of selected tracks.
Display, create text file listing info of dead tracks
Batch set new Last Played/Last Skipped of selected tracks
Correct song titles listed as "Artist - Song Name"