I just had an idea.... Someone needs to make a car alarm app for smart
phones. It can use the microphone to listen for breaking glass, the
speakerphone for playing pre-recorded messages (step away from the
vehicle, the police have been called), the camera can sense movement
inside the vehicle and the GPS can sense (and report) movement of the
vehicle. All of this information can be sent in real time to the other
phone that you carry with you. Installation is as easy as turning it on
and tossing it in the seat! Compatible with any car! Battery backup!