Thanks to SEW for pointing to this outstanding article about MSN Virtual Earth—its history and technology—and its competitive positioning against the upcoming Google Earth. The article has a couple of points wrong, though. Twice, it mentions "unique" features of Virtual Earth. One is search results repopulating new imagery as the user scrolls the terrain. The second is the overaly of a map on top of the satellite imagery. The current iteration of Keyhole (which will eventually become Google Earth) certainly repopulates search results during flyovers, and does overlay certain map features (streets, in particular). There is room for improvement, especially in the accuracy of the overlays. The real question is whether Virtual Earth will be interfaced with a flyover machine, as Keyhole is (and Google Earth will be). The article makes it sound as if Virtual Earth would be merely an enhancement to Microsoft's mapping service, not also a dedicated flyover program. If so, Google has a decided competitive advantage. Also, though Virtual Earth's sample images appear wonderfully sharp, and the 45-degree angle reveals building faces better than in Keyhole, they are black-and-white images.

This ultra-realistic geographic search competition, which has sprung up quickly, is going to be fascinating to watch. It is nascent; revenue modeling and varied mobile consumer applications are all in the future.