A device called Garmin Tracker will always keep you informed of where the "observed object to which it is" attached ". As you might guess, the device computes its own location using the system GPS, then the gadget sends data (via the mobile Internet, if available network) to the server Garmin, where you can watch it on a convenient map.

This service allows you to configure Garmin Tracker so that if he leaves the specified area, then automatically send you a notification via email or SMS.

Garmin Tracker cost $ 200, and you get a free annual subscription to the service. Get ready, bad husbands and wives!