I have started a forum toplist. The only requirement for joining is a link back. There are several options for you to add the to your site, including an instant rating button to increase your site visibility. No adult sites allowed.
You can list more than one forum under a single account as long as you add your link back on each of them.
This site is new but professionally submitted monthly, and I plan to advertise with Overture in the very near future. I hope you will take advantage of this traffic building tool.