I love the theme/template you're using. I would suggest a CMS, XOOPS is meant to be good. So is Joomla and Drupal (I'm a Drupal fan myself).
Drupal has a module which is sort of like Forums on steroids. Its called Organic Groups. Examples exist on many drupal sites, like:
http://teamsugar.com/groups
http://groups.drupal.org/groups
http://www.pponline.co.uk/group
Basically, people can create groups and others can come along and subscribe to them. This enhances the feeling of community and "belonging". It also means that posts into a group dont just have to be threaded conversations like this - they can be anything (you could post a blog item into a group, or a video... or a poll!)
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