Accessboards.com Want to add a bulletin board to your site? This looks like a good one, and it's free. Features include registration of members, optional HTML, bad language censoring and full statistics on who and how many people are visiting your board.

Boards2Go.com Another free source for message boards for your web site. These boards are easily customizable.

Delphi.com If you have a web site you can add a free forum to it courtesy of Delphi. Just fill our a short form and before long you will add a new level of interactivity to your site.