Right now, there are 1.5 million computers in the U.S. that are suspected to be infected with malware, although that figure seems inordinately low, but we'll come to that in a bit. I know this because of Malware Tracker, a Google Maps creation by the Enigma Software Group that uses data from its SpyHunter software to work out just how many computers worldwide have nasty worms and Trojan horses lurking inside them.
As it uses the Google Maps API, it's possible to zoom right into specific neighborhoods and find out just who's dirty and who's not. You can separate the results into confirmed infections and suspected infections, as well as isolating different types of malware.
There is a caveat to all of this. As the information comes solely from Enigma, it's going to be inordinately low: Imagine what the figure would be like if firms like McAfee and Symantec added their data to this--the map would be groaning beneath red-and-blue icons. Treat this as a promotional tool for Enigma, but hope that there's someone out there who's into the whole malware issue enough to adapt this into a universal tool and give us some data that is more realistic. I think it would be scary.