what I like about this is the rider has an iPhone so while the cabbie is transporting him the rider can see the Google Maps routing path, and compare that to the actual position and route the cabbie is taking. If they differ significantly the rider can know he's getting scammed. Technically the rider could do this without UberTaxi as long as he has an iPhone, but since UberTaxi depends on the rider having an iPhone app, it comes along for free.