http://www.bbmark.com/

Turnkey site that's only a few days old. Includes the software to install a basic forum for users. The forum itself requires no prior knowledge of HTML and it's easy to set up and run. You could always replace the current script with another. It's had around 6-7 uniques in the past week since it's been online. No promotion has been done but it has been submitted to Google and proper meta tags added. No income currently either.

Taking offers. Payment via Paypal.