Consumers stand to benefit tremendously from Google, Microsoft, and Yahoo!'s competing efforts to turn online maps into browsers that organize information along geographic lines. Google offers a search-and-mapping service, Google Maps, that combines satellite pictures, map dragging capability, and pop-up balloons displaying locations turned up from local queries. Microsoft's MSN Virtual Earth, meanwhile, features satellite photos, pan-and-zoom, and interactive search listings. Yahoo!'s SmartView application lets users highlight points of interest through a series of buttons presented next to a traditional map. Google, Microsoft, and Yahoo! have all issued application programming interfaces allowing outside programmers to create online services that exploit the companies' map programs, and the results of location-driven queries - not to mention the precision of contextual ads - are bound to improve as more information is geotagged. One of the biggest advantages of modern online mapping systems is their ability to enable users to overlay their own data on maps. The latest interactive map services were made possible by improvements in hardware processing speed and storage capacity, the emergence of basic mapping-software standards, and database owners' realization that outside access to their information repositories would improve their bottom line.
Technology Review (a magazine by MIT) has a cover story called "Killer Maps" on new Internet mapping technologies highlighting Google Earth. This is an excellent story not only highlighting Google Earth, but also talking about the interfaces (APIs) Google and other mapping tools are creating allowing programmers to customize the maps. This is a long article with lots of examples of how these tools are being used. The first "page" is dedicated to an example of Google Earth being used to plan a trip to Chicago.