I threw together a quick web page to convert rtttl ringtones to gcode so that users can play ringtones on their printers. It's great for print finished notifications. You need a printer firmware and that supports M300 and a buzzer. I've put in pull requests for Marlin and Repetier that add M300 support.

You can use the converter here: http://ddrboxman.github.com/RepRapRingtone/