external sound buzzer via Serial

[jasonwood]

I'm looking for a horn/buzzer/bell/whistle that can sound in response to a serial command (sent through Troi serial plug-in).

This is for an application where a user will often scan dozens of bar codes in a row without looking at the screen or necessarily hear any error tones generated by the computer's speakers.

Anybody know of such a product?

If they don't exist, I guess the next best thing would be an RS-232 device that could open/close a circuit, which I would connect to some kind of buzzer...