The Netduino GO! Piezo Buzzer Module provides a single muRata PKM13EPYH4000-A0 piezo buzzer (actually a sounder) for your Netduino GO! system. The driver for this module is included in the Netduino 220.127.116.11 SDK.
View a video showing this module in use.
If you already are using the two ribbon cables that came with your Netduino GO!, be sure to purchase more so that you can plug in this module.