Oh and if you take the mercator projection approach: Here is the formula derived to actionscript. Actionscript Mercator Projection
var lattitudeAngle:Number = 0.8 * Math.log(Math.tan((Math.PI / 4) + 0.5 * (pointLat*toRadians))); I got this formula from a great Java Map library: http://www.jhlabs.com/java/maps/proj/
