MrMrBen asks: "I've been seeing ads for Zipcar on the subway in NY. I didn't realize that it's actually out there and working. Apparently, you make a reservation on their web site, show up at the car, wave your membership card over the windshield and it unlocks for you. Does anyone know what kind of wireless network they use? Can they track the car while you're driving it? Have people been using zipcars, and what have their impression been? Is this the future of cars for city dwellers?"