In case you haven’t read about this on another blog yet: Google Maps.
I’ve just played with it a little, and I’m very impressed. You don’t need to re-load the page at all the navigate, and you can simply click-and-drag to move along the map. Same goes for zooming. It’s all done on the fly, and there is no need to wait for the page to reload.
I wonder what Google wants to do with this. It can’t really make them any profit, so I wonder why they would launch such a service. Same goes for a lot of other Google services to be honest.