DTMF Shield for Arduino

This DTMF Shield is a Dual-tone multi-frequency signaling module decoder for Arduino With it's audio connector you can decode the crazy funny noises common phones make. If you are not sure what I'm talking about, imagine a home phone while pressing several of its keys. These Touch-Tones have a specific frequency or sound that this module can decode. This Shield is an Audio code system that will allow you to send commands to your Arduino via Audio signal.
Together with GMS / GPRS / GPS shield this module can communicate your Arduino with any phone land line or Cell phone in the world, within GSM signal range. Which goes as far as your cellphone.