Research in Motion has introduced a new feature in its Locate Service offering  cell tower geolocation capability to developers for free.

Users can be indoors with no GPS coverage, but your app will still be able to guide them to restaurants or points of interest (POI) around them. Although the accuracy of the fixes obtained from the Geolocation service may not always be as high as with GPS, it has use cases for apps that require highly accurate GPS fixes as well as apps that do not. Apps that require high accuracy can use this service to quickly show the user an approximate location while it waits for a more accurate location fix using GPS. This can offer a huge user experience improvement. For applications that do not require high accuracy, this service can be leveraged as a simple yet effective mechanism to provide location information.

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