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
Search for lyric sites with Google using info from the current or selected track
Perform search-and-replace on text in your choice of tags
Remove iTunes tracks disassociated from files
Display, create text file listing info of dead tracks
Download any or all available subscribed Podcast episodes not yet downloaded
Create text file listing tracks common to and exclusive to two playlists