I believe these boards are on phpBB2, there is an addon for google maps that might be worth checking out:
http://www.phpbb.com/community/viewtopic.php?t=318805
Allows users to embed google maps into their posts.
There is a beta version for phpbb3 here, in case you were thinking about upgrading the forum software:
http://www.phpbb.com/community/viewtopic.php?t=454956
Just a thought.