Last year, a Google maps for mobile upgrade included the "My Location" feature. It allows users to find out where they are even if their phones don't have GPS. Now Google is opening up the application to 3rd party developers.
My Location uses cell phone towers to approximate the location of a cell phone user. Writing on the Google mobile blog, Zhengrong Ji and Ravi Jain of the Google mobile team explained:
"If the phone has GPS, the Maps application on the phone sends the GPS coordinates along with the cell ID to the Google location server. Over millions of such updates, across multiple phones, carriers, and times, the server clusters the GPS updates corresponding to a particular cell ID to find their rough center. So when a phone without GPS needs its own location, the application on the phone queries the Google location server with the cell tower ID to translate that into a geographic location, i.e., lat/long coordinates."
Gears for Windows Mobile and Android already have location APIs, and Google says they expect to see the My Location API implemented on the Apple iPhone applications as early as this month, as Apple launches their highly anticipated store for iPhone apps.
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