Jeff, I started and studied these since way back in 1997! There were even some CMS packages back then for doing just that....
I'm going to issue a little warning though. I'm a bit of a muckraker and political junkie, so I naturally got into BIG trouble with my board in our town of 25,000 in NJ. The pols didn't like it, nor did the ruling political party! They actually spoke out against me and the board in the local paper, etc.
But I stirred up a LOT of stuff. We even got covered by the Philadelphia papers (15 miles away), etc.
It would be hard to create a forum where some type of politics will not enter the mix - especially if the particular town (like most) have their share of corruption, nepotism, waste, etc.
I put up a forum on my board in 1998, but had to pull it down. I figured out that a blog fit it MUCH better - because that was I could write the main subjects and others could comment.
Just giving fair warning. There are often secrets under the covers in small towns!
Edit - all in all, my suggestion is that a full forum type is the wrong way to go, and maybe a blog-type is better so that you control the mix!