Just for fun !
We can can track people through cell number, based on GSM mobile phone tracking system via the GPS-TRACK satellite network.
Based on repeater triangulation, the system tracks mobile phones using GPS and GSM technology.
Global Positioning System - GPS - devices have become everyday items to many of us as their cost has fallen. These devices communicate with geostationary satellites, which tell the device, exactly where on Earth it is. The potential applications for this knowledge are endless. If you know where you are, where you were and the time in between then you know your speed exactly. If you know where you are then others do too.
Go to : http://www.sat-gps-locate.com