Absolutely. In fact, from the homepage, there is a page that you can grab banners and buttons to use on your site. The more crosslinking to this site, the better. When you do link it, drop an e-mail to the webmaster at jay-at-originaltrilogy-dot-com and let him know as he likes to maintain a master list of sites that are linked here.
Granted none of the buttons say anything about the forum, but if you like 'em, you may as well use them.