This script applet stores the tags of the selected iTunes track (as a script property). Later, when you select another track and run the script again, it will paste the stored tags to that track. You are able to choose which tags you want stored.
(Note: In order to launch this PowerPC-era script on an Intel machine, it must first be opened and then saved using AppleScript Editor, which is located in your /Applications/Utilities/ folder. More information is here.)