I've had a play around with it and it's really neat. You can download lots of different map backgrounds. A good feature is the 'prediction' thingie where you can get the prog. to list when a given satellite will be coming overhead (and illuminated for viewing). It gives times and alt/az bearings etc.
I'll definitely have to send the author a postcard for his effort. It's people like him that keep the internet real.
Another useful tool hehe...
