A tracking project based in amsterdam has produces a really nice visualisation of the GPS log data. A couple of people tracking themselves on their daily commutes presumably with a igotU GPS device.
The visualisation is done in processing.
It is amazing how quickly the structure of Amsterdam becomes visible. Compared to the London UrbanDiary map here in Amsterdam a much clearer urban structure shows. This is probably down to a number of factors, for example the urban morphology is fundamentally different between Amsterdam and London and the mode of transport is probably similarly different. A lot more bicycle transport, which makes for a more divers picture, than by using public transport or even traveling underground with the tube.
But because of this is makes for a really nice visual comparison between the two.