Oh, since this thread popped up again, I thought I'd add the latest. I started a forum for the local community about two weeks ago. At present, it's just a demo site, designed for the local leaders to look at.
And ... it only took the spammers a week to find it and start posting. I deleted the posts and then immediately altered the registration procedure, which stopped the whole business in its tracks. Even so, it is kind of depressing to think that one can't seem to do anything for the good without spammers.