Approx distance to nearest mobile mast

I stumbled across a website that apparently allows users to work out how far the nearest mobile phone masts are. Is there a method of working out this distance hard-coded in android? (Or does anyone have any suggestions of how to complete this?)

One solution could be to disable GPS positionning and enable only cell positionning. I doubt there any triangulation of positionning in that case and the device geo fix will be the one of the closest mast. After that, you use GPS on and get real position and calculate the distance using euler distances.