tracks the last four hours of taxi movements in San Fransisco. Taxis that are equipped with the proper GPS equipment leave a path indicating if they have a passenger or not.
Even at 3:53 AM PST the map is still interesting to look at. The map is zoomable and pannable. As well, Also worth a look is a shortened time-lapse animation
showing the movement of one cab throughout the day and cab speed
. Similar to the animated map of courier movements posted earlier
By way of BoingBoing