Well, unless it's already there as an option in member search that's merely disabled right now, someone would probably have to write the code to make it possible. Which would likely mean that it can't be done in the near future, unfortunately; the folks who could do this are apparently already buried under things that need to be done, AFAIK.
Hm... You could start a thread to ask about where folks live. Maybe even try to find one of those thingies on the internet that lets people show their location on a map. Just my 2 cents, though.