I have found a very simple solution to this.
BuddyMapping: Create your own Maps!
It only took five minutes to create a map. It does need an email address to set up. I thought it would be good to have a map created linked to the forum admin email, titled "CerocScotlandForum". Any forum member can go to the site and any a dot with their forum id as a name.
People can optionally add a picture or facebook. webpage link to their location.
There is no overhead or waiting for the administrator to add the user to the map. People can also remove or move their locations.
It would be good if a forum moderator kept an eye on it though.
A link from the forum to the site could be added to the User CP to encourage use.
Any problems with this?