If someone can get this thing to work, it would be the closest thing on the web that will do what you say. I think it would be great. Even if someone doesn't really want to show their homestead, they could at least put a flag on their hometown. This program/website uses Google maps and puts flags with descriptions that you can edit. Basically exactly what we have been looking for. I've lost patience with it, maybe someone is smarter than me.

Website here

Another Possibility

The second linked page will also work if you put Agtalk in the message field when you add a new flag for your location. Then if you go to the Tags tab and select Agtalk, then only Agtalk users would show up. Kinda neat.

Never mind the above. I found out that just using Google maps was much easier. Looks like you can create your own maps now.