Didn't we have that already when there was a bunch of independent taxi/car companies in each town? You could call one of them up on the telephone (in a decentralized manner). They could drive to your location (via a decentralized route), and take you to what ever decentralized location you like.

Heck, if you even get banned by one for puking in the car, you can always just call a different company the next ride.

So there, I just invented it. I'm going to call it "DUber".