The only work you need to do then is cacluate the GLatLngBounds representing your 10 mile radius. Now, going back to your question about Google Latitude using a scaled circle image (and this is probably the most useful to you): if you know the radius of your circle will never change (eg it's always 10 miles around some point), then the easiest solution would be to use a GGroundOverlay, which is just an image url + the GLatLngBounds the image represents. 'Hagstroms map of 50 mile radius from New York.' The New York Public Library Digital Collections. However, this guy did it using vml for IE and svg for other browsers (see 'SCALED CIRCLES' section). Lionel Pincus and Princess Firyal Map Division, The New York Public Library. They only give you GPolygon which they want you to use to approximate a circle. The catch is, google maps doesn't give it to you out of the box (they want to stay as close to GIS values as is pragmatically possible). Inner Harbor has been a seaport since the 1700s and stands as a city landmark and the center of tourism for Baltimore today. In other words you can draw a scaled vector circle on a google map. Baltimore, Maryland 39.3 miles from Washington, D.C. And if you have a flat coordinate system you can draw 2D objects on it all you want. Having said that, realize that google maps is projecting the earth onto a flat surface (think 'unrolling' the earth and stretching+flattening until it looks 'square'). Harbor has been a seaport since the 1700s and stands as a city landmark and the center of tourism for Baltimore today. The more points, the more it'll look like a circle. Therefore a circle (in terms of a a shape projected onto a sphere) is something that must be approximated using points. You can use Google Maps to experiment with drawing radii from your office to determine air mile distances. You have only those rudimentary values to work with. So, if your headquarters is located at Point A, an air mile is the distance you would travel in a straight line to your destination Point B. In spherical geometry shapes are defined by points, lines and angles between those lines.

Map of 100 mile radius of baltimore