According to their corporate blog, Google has aquired Keyhole.
If you’ve never tried this product, it’s quite impressive. It’s similar in concept to NASA’s World Wind, but with a much more refined interface and supported infrastructure. Basically, you start out looking at the Earth, and you can zoom to any level, search by address or place name, etc. It provides endless hours of “hey there’s my house” fun. On the practical side, it’s useful for checking out real-estate & vacation spots, and I’m sure Google has lots more in store for us.