Here is an AppleScript designed to display your current iTunes song on an LCDproc server. It uses expect to control a telnet session to the LCDproc server. You do not need Growl.
You must open it in Script Editor, save it as an application and select "Stay Open" in the save dialog. Then you can put it in your iTunes Scripts folder so it is accessible in iTunes.
Download the iTunes LCDproc AppleScript.
Update!I updated the script so it uses very few processes now.