The system allows you to create a virtual GPS fence and can automatically alert you if the tracking collar leaves the boundary of that invisible fence. Unlike other virtual fence systems, this one uses the GPS-enabled receiver as the reference point. So if you're carrying the receiver and are moving (i.e. on a hike or walk), the virtual fence boundaries move with you.

You can track up to three collars with one receiver, so keeping tabs on the whole family at the mall should be that much easier.

The bad news? Apart from the $500 price tag (plus $160 for each additional GPS-enabled collar), the collar and receiver communicate with each other via radio, not GSM, and can only communicate with each other up-to 1-mile away. If you've that kind of green, and can live with a 1-mile range between the collar and receiver, then head over to RoamEO's website to order yours. Dog owners may also want to check out Garmin's Astro system.