Inventor: GoCar Rentals
Availability: Now, $40 for one hour
To Learn More: gocarsf.com
Forgot the map? Left the guidebook at the hotel? No problem. The GoCar is a three-wheel tour guide equipped with a GPS system that not only tells you where to go but also describes the sights once you reach them. The brainchild of Nathan Withrington, a pilot and engineer from Britain, the GoCar speaks directions out loud. Currently available only in San Francisco, it goes up to 35 m.p.h. and travels a 12- to 17-mile loop.