Real-Time London Tube Map

Via many sources (for example, Ed Parsons and Google Maps Mania), this live train map of the London Underground, showing the real-time position of each train. It’s a mashup of Transport for London data with the Google Maps API, but its execution, and the speed at which it was put together (essentially, a few hours over the past weekend, and it’s already had some improvements since I first saw it yesterday), is what makes it noteworthy.