RepRapRingtone
RepRapRingtone converts rtttl ringtones to gcode. This is greate for using the numerious free ringtones online as finish or status sounds for your printer.
This requires your firmware to support M300 and your printer will need a buzzer.
It just uses javascript so you can use the converter in your browser here: http://ddrboxman.github.com/RepRapRingtone/