Google maps makes Application Program Interface (API) protocols readily available, so enterprising code jockeys have spawned hundreds of integrated programs (like this one).
Here’s two that I find useful. http://www.zeesource.net/ provides a utility to ‘pin’ multiple locations on a google map. Here’s one I drew with the addresses of 4 potential quartet singers in order to figure out the best place to meet.
There’s a cool tool at http://maps.huge.info/; enter a zip code and you’ll get a refreshed page and an outlined map of the zip code for which you’re searching. Add more zip codes to compare locations or expand the area. You can zoom in on it a big and still have the outline.