Bing Maps are by far the best thing to come out of Microsoft's insistence to take on Google in search. The maps and aerial imagery is on par with a lot of the work that Google does in the field. Microsoft just finished up their latest Bing Maps project and the results are pretty awesome.
Microsoft recently wrapped up the Global Ortho program here in the U.S. The project sees Microsoft capturing aerial imagery of every nook and cranny in the continental United States. To prove their point, Microsoft provided a map that shows how much land they were able to cover:
As you can see, they were able to get the entire U.S. except for two small areas in the Southwest. Microsoft says that they got clearance to photograph everywhere in the U.S. except for Area 51 and the Vandenberg Air Force Base. The larger of the two yellow areas is Area 51. I didn't realize the U.S. government needed that much land to hide the existence of alien spacecraft.
All joking aside, Microsoft got some great aerial imagery. They were able to capture the entire U.S. at a 30cm resolution. They concede that other people have captured aerial imagery at higher resolutions, but nobody has captured the entire landmass of the continental U.S. at 30cm resolution until now.
Let's do a little comparison test for now. Here's Google's aerial imagery for the University of Kentucky with a close up on William T. Young Library.
And here's Bing's GO shot of the same building and surrounding area.
In all honesty, it's hard to tell which is better at this distance. The Bing maps provide a much better view of really close up shots, but Google trumps that advantage with their impressive Street View.
Comparisons aside, the Bing Maps team has been able to get some great imagery of our country. It's even more surprising that they were able to get such great shots of lesser known areas. It's still unfortunate, however, that the Bing Maps team were not able to get shots of Area 51.