Safety tech is progressing in every field imaginable, especially with the aid of computers and telematics. But what if you don't want to fork over for the latest vehicle to get the ability to track your teen's driving? Hammacher Schlemmer has the answer.

Innocuously named the Driving Activity Reporter, the GPS-based system employs a simple flash drive and a magnet to surreptitiously record the car's activity. Up to 100 hours of drive time can be recorded, and later analyzed on the provided software.

The routes can even be overlaid on Google Earth plots to see exactly where your kids have been going. If only it could record what went on inside the car, right?

Ford has been working on similar technology through its MyKey system, which lets parents control how fast their teens can drive or how loud the stereo can go, as well as permanently engaging traction control and encouraging seat belt use.

Some insurance companies have also been exploring the use of built-in GPS units to track actual distance traveled for use-based insurance rates, but they insist that such systems record no location-based data. BMW is even showing off a system that learns your behavior and pre-selects your next destination.

The Hammacher Schlemmer system, however, is only useful after the fact - it has no prohibitive capabilities like Ford's system. Still, it's easily installed in almost any car, and can be used in multiple vehicles if necessary.

To help boost battery life and increase recording times, the system is motion-activated and goes into sleep mode when idle for more than two minutes.