I'm writing a new LL management system myself within the next few months.
One handy feature I'll be sure to implement in my own is a method for allowing users to report a bad/abusive link. If you implement this make sure you make the user tell you why they are reporting the site, maybe with a form (comments box, radio buttons with pre defined reasons, etc.). If you don't make them do this they will click and report links for the hell of it and it will be useless.
Users like clicking things to see what they do. Make them do a little work and they won't click more than they have to.
I love this monkey.