title: What is a good algorithm for mapping GPS coordinates to screen locations when using Google maps?
body: <p>I need an algorithm that will convert a GPS coordinate to a screen location on a displayed google map.  I would think this would be simple- get the coordinates for the four corners of the displayed map, find the differential and create a scaling factor for a pixel location on the screen.  Is this correct or am I missing something.  I'm know this has been done ad nauseum but I am hoping I can hear from someone who has implemented it successfully or has a resource for implementing it.     </p>