Awhile back I wrote about a USB key that works as a vehicle tracking device. It had gotten some press as a tool for solving a murder. Beyond helping the crack force of CSI:Miami, the device is actually a compact useful GPS for more mundane functions. It’s Google Earth Compatible, meaning you can visually map data collected while the GPS is in yoru car. The small size is easily concealed, meaning you could use it to track your spouse, teens, or anyone else you happen to distrust in this paranoid world. I could certainly see this coming in handy for rental car companies concerned about you taking their car out of state (although I’d hope they are required to disclose such tracking). If you do travel frequently, carrying a USB key GPS tracking device would be a convenient way to track mileage without having to write everything down (just be sure to turn it off before driving the company car to the local strip club). Tracking is accurate down to 2.5 meters, or about 10 feet, which goes beyond the accuracy of most cell phone GPS solutions. At the time I originally wrote about these, the options for getting one were fairly limited. Now there are a number of options listed in a handy directory of dealers selling GPS Vehicle Tracking hardware.