I'm sure the cat's out of the bag, but Google Earth is a pretty amazing application that's hot right now.
I can't even imagine the code behind the scenes running the map movement.
Check it out (http://earth.google.com)
Coolest.Toy.Ever!
Other than viewing a few kind of cool images, I couldn't find any usefulness to the product. It looked more like a technology showcase or something.
Anyway, if I had to take a guess at the code used in the client, I'd guess it's SVG and VRML for the high altitude images and VRML, SVG, and some graphics renderer for the low altitude images.
SVG is really hard to use by hand. It means scalable vector graphics and is a really neat standard created by the W3C that seems like a replacement for a lot of flash stuff. Anyway, the best way to use SVG is via tools, and even the W3C says SVG wasn't really created to be used by hand.
PS: The SVG info was just an side note I had.
Like Bryan said, it's a pretty cool toy.
I can't say it's all that useful. It's pretty cool for driving directions, because it shows the road and you can have it drive it too, so you can get a better idea how it goes. Pretty much though, it's a cool toy.
I don't see this tool being particularly useful at the moment. However, it's really freaking cool and I can see how in the future this sort of technology could be a standard for maps.