GPS Technology

Very soon, the most common phrase transiting through mobile phone networks will no longer be "Where are you? but "I see you."

While satellite navigation via Global Positioning System (GPS) have been helping earthbound humans to visualize and plot everything from U.S. military movements to lost hikers since the 1970s, GPS and other mobile location-based services (LBS) have only recently begun to infiltrate our personal handsets.

"Many phone companies offer a cell-based location system," says Lawrence Cheung, principal consultant of the Hong Kong Productivity Council (HKPC).

"The system works by locating the strongest nearby cell signals that are visible by the device's antenna, which can determine its position with an accuracy of around 200 meters. Hong Kong has about 1,500 cell towers."

to read more plz visit: http://www.cnn.com/2008/TECH/06/19/digitalbiz.gps/index.html