Checkout the new http://directory.linkexchangeforum.co.uk Website Directory Service

If you cant provide a backlink for whatever reason for the free listing then they offer a cheap as chips 25p submit option fee. If you compare this to the cost of 1 click on a Google ad back to your site, then just the one click from the directory and its paid for itself. Also you will still have the backlink to your site to hopefully improve your website PR. so everyones a winner lol