Taking a page from Wikipedia, Internet users are harnessing the collective knowledge of millions and applying it to maps. On the rapidly growing "GeoWeb," surfers create custom atlases using mapping technology by Google, Microsoft, Yahoo, and others. The user-generated maps can highlight anything from stores to previously unavailable maps of endurance horse races, the Times reports.
A variety of maps can be "mashed up," with each layer displaying a different element, like hotels, restaurants, crime statistics, or school rankings. One web cartographer mapped out the spread of vandalism in his town. Microsoft has created detailed visuals of 100 cities and ultimately plans to make "a digital replica of the world in true 3-D," says an exec.