I don’t think it is too difficult to work out, and it is only something that each member would need to do once. It would also be entirely user driven (other than perhaps pointing people towards it – you could add a link to the navigation bar at the top of the site), so wouldn’t require maintenance on the part of the admins.
Also, people can choose exactly what information about themselves they put up. And anyone worried about revealing what street they live on can just place their marker at a city center location, or whatever distance from their home they feel comfortable with!
Finally, it could also be made a private map, so that only people who have been given the URL can find it (ie it won’t show up in search results, etc).
Was just an idea anyway, as people were requesting some way of finding other members 🙂