Driving Activity Reporter
Keep track of your driving history with this Driving Activity Reporter ($230). Powered by an internal 16-channel GPS receiver, the USB device mounts anywhere in your car and records locations, routes, date/time, and speeds of every trip you take. It stores the reports — up to a 100 hours of them — on its built-in flash memory. When you're ready to see your stats, just pop into your computer and use the included software to examine it. Google Earth integration makes things really interesting. Also great for catching cheating lovers.