Look at the source for your forum summary page and you'll see the javascript code that reads the user cookie. You can use that code anywhere on your site to check to see if someone is logged in or not and include links to the log in page. If you want people to be able to log in and return to the non-UBB page that they came from, you'll need to hack ultimatebb.cgi and change:
Otherwise when they log in, it will just take them to the forums and not back to the page they came from. Keep in mind that reading cookies with javascript as a way to keep people out of members only html pages doesn't really work that well. They can just turn off javascript on their browsers and go anywhere on your site if they wanted.
