I'm not a big fan of the login scripts, seems rather secretive to me and doesn't promote membership IMHO. Why would someone signup when they can't even get a glimpse of the content? May be a good idea to add the info about the Guest login to the opening screen so they can at least get in to see if its worth joining.
My only other comment would be to consider changing the background graphic, seems too busy to me. However, I will say the page loaded fast so its not hurting your board performance.
