title: How does Google Maps know my position?
body: <p>I have a nokia 5500 sport mobile phone, and I found after i installed google map, it can automatically locate to my current position.
  and I want to know how google map get my position and mark it on the map ?
  How can I programming implement this feature with symbian C++(nokia 5500 's operate system is Symbian 3rd).</p>