In conjunction with the application Growl, this AppleScript will show information about the currently playing track in iTunes.

itunes-information.applescript

set crlf to (ASCII character 13) & (ASCII character 10)
set escapeChar to ASCII character (9)

tell application "Growl"
	-- Make a list of all the notification types 
	-- that this script will ever send: 
	set the allNotificationsList to {"iTunes Playing Track"}
	-- Make a list of the notifications 
	-- that will be enabled by default. 
	-- Those not enabled by default can be enabled later 
	-- in the 'Applications' tab of the growl prefpane. 
	set the enabledNotificationsList to {"iTunes Playing Track"}
	-- Register our script with growl. 
	-- You can optionally (as here) set a default icon 
	-- for this scripts notifications. 
	register as application "Growl iTunes Notification" all notifications allNotificationsList default notifications enabledNotificationsList icon of application "iTunes"
	set title_text to "Nothing playing"
	set body_text to ""
	set has_artwork to false
	tell application "iTunes"
		if player state is playing then
			set trck to current track
			if artworks of trck is not {} then
				get artwork 1 of trck
				set pic to data of result
				set has_artwork to true
			end if
			
			get name of trck
			set title_text to result
			
			get artist of trck
			set body_text to body_text & "Artist:" & escapeChar & result & crlf
			
			get album of trck
			set body_text to body_text & "Album:" & escapeChar & result & crlf
			
			get time of trck
			set title_time to result
			set body_text to body_text & "Time:" & escapeChar & result & crlf
			
			
			get rating of trck
			set rate to result / 20
			set body_text to body_text & "Rating:" & escapeChar
			
			repeat rate times
				set body_text to body_text & " * "
				--				set body_text to body_text & " * "
			end repeat
			
		end if
	end tell
	
	if has_artwork then
		notify with name "iTunes Playing Track" title title_text description body_text application name "Growl iTunes Notification"
	else
		notify with name "iTunes Playing Track" title title_text description body_text application name "Growl iTunes Notification"
		"iTunesLibraryPlaylistIcon.icns"
	end if
	
	
end tell