I've been on holiday and at a conference for the last 10 days but back in the saddle now.
My boss has a road map of Helsinki on one wall of his office which has become familiar after seeing it so often. It was therefore distinctly bizarre to come across a map showing Helsinki bus positions in that city (courtesy of Ed Parsons' blog). Its a great example of real time map use but If you watch it for a while you'll see that the positioning system isn't accurate enough to produce the true, smooth path of the buses, the bus icons jerk in random directions giving the bizarre impression of shoppers thrown wildly against the windows.
I mention it as its a lovely example of design; subtle colours, clear icons and the arrow showing direction of movement are all excellent. It also showcases one of the two features of Google Earth/maps that I consider 'killer apps': Real time plotting of features. With mobile web devices becoming ever cheaper and more common being able to check where your bus/plane/friend has got to via your mobile phone is bound to be hugely popular.
Update: 3/10 The link to Ed Parsons' blog has been corrected, thanks for the heads up Frank.