First, there was Google Maps, a nice little web application.
Now, there is Google Earth, a nice big old-school fat client application1 which will totally and utterly rock your face off.
I was going to make a clever segue into the lyrics from this Kate Bush song, but words fail.
Guh.
1 A nice, fast modern Windows PC is required. Supposedly, they are working on a Mac version. We’ll see!