We honestly dont need anything at the moment, the forum is heavily guarded with Gargoyles, land mines, and other booby traps
The feature that Kissfreak mentions is a program I know...it is called "Miserable User". It is designed to make the "troll" or whomever is making all the trouble feel "Miserable" if he/she attempts to log into the forum who uses the miserable user program. This progam is evil, and will make the person think they have a virus or something.
I personally dont want to use anything like this, but it is sorta funny when you think about how miserable you can make them with the tricks and stuff the program does.
As far as screening new registrants, we can place all new members in "moderation", which means that they register, and can make a post but the post wont be seen until a moderator approves it and checks to make sure it is a valid member. I personally find this extremely restricting, and is only used under certain circumstances. We dont want to encourage spammers, but yet we dont want newbies to think the forum is a "pain in the butt" to join.