The general public is mad about GPS sets for cars: they were top of the favourite Christmas presents last year. Really easy to use, these sets are ideal because they don't require a subscription. The user just turns on the machine, enters a postal address, and the computer calculates in real time the route using various parameters (quickest route, shortest route, and so on). Once the driver has done this, all he needs to do is follow spoken and visual directions, presented on the map on the screen.