Uber is a taxi/livery service that magically uses technology to do things that shuttle/livery services in major cities have already been doing for years.
The difference is that: (1) Uber is a startup, (2) Uber is backed by YC, (3) Uber lets anyone be a driver, (3) Uber ignores the laws and/or regulations in the cities that it operates until it gets caught and threatened with major lawsuits/fines, and (4) Uber promises 10-minute pickups (sub-hourly timeframes between reservations and pickup are the defining line between livery services and cab services in many cities).
The difference is that: (1) Uber is a startup, (2) Uber is backed by YC, (3) Uber lets anyone be a driver, (3) Uber ignores the laws and/or regulations in the cities that it operates until it gets caught and threatened with major lawsuits/fines, and (4) Uber promises 10-minute pickups (sub-hourly timeframes between reservations and pickup are the defining line between livery services and cab services in many cities).