Touting it as an environmentally friendly alternative to cars, inventor Dean Kamen finally unveiled his mysterious creation to the world this morning. The gizmo — which has gone by the codenames “IT” and “Ginger,” but will be marketed under the more prosaic “Segway Human Transporter” — turns out to be a one-person, two-wheeled, battery-powered scooter that looks something like a push lawnmower. Kamen said the Segway “will be to the car what the car was to the horse-and-buggy,” adding that it “makes no sense at all for people in cities to use a 4,000-pound piece of metal to haul their 150-pound asses around town.” The 65-pound Segway can attain speeds of 12 miles per hour; the battery charge lasts about 15 miles, at about 10 cents a charge. The machine apparently handles snow, ice, and stairs with ease. Cost? $3,000 a pop. The U.S. Postal Service and are among the first customers.