Hello Mr. Rawles,
I wanted to share a great web site for calculating distances, etc. on several different mapping systems: GPSVisualizer.com. You can overlay your results on Google Maps or any of a bunch of different map types, including Google Terrain, which I like. It will compute range rings from a lat/lon or an address, great circle distance from an address / lat/lon to another address / lat/lon… etc. Great for showing folks exactly how close they really are to a large population center or other nasty place! – Rick in New York