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.
OS X 10.6 or later only.
Tools in the Rename tab operate on the selected playlists' names
Export album-artist pairs to tabbed file
Set iTunes to play within 24 hour period
Swap the name with the artist of selected tracks
Re-associate batch of dead tracks with files from selected folder
Display, create text file listing info of dead tracks
Remove iTunes tracks disassociated from files