We need better maps IV

So I am in the plane reading the newspaper and bam, what I was describing earlier is now sold as a product. It is called TomTom. It is a software for mobile devices but it has several problems. First it looks like it is for cars, so it won't work for walking tourists in Paris (specifically having to carry a battery for the gps receiver). Second, it is only for one region of the world. Third, it costs 499 euros and as far as I understand it doesn't include a PocketPC/Palm computer with it. So the final bill for it is pretty steep and I don't see how the price could go down. It is a far cry from a 10 $ solution....