Another option for a free (free as in advertiser driven) community site is to create your own social network site on
www.ning.com
Examples of community sites using this platform include:
www.montpelier.ning.com
www.montpeliervillage.ning.com
OK if you're promoting the site in other ways apart from search engines (especially if it is a local community word of mouth thing), and you could always use a different domain name and redirect (if you don't like the ning.com part).