I want to get a ban system running on my board that will say to users why they were banned and how long for, and possibly saving the information to a database table. The DB table thing is because I have more than 1 board, and I want a global ban to work without me having to copy paste bans all the time.

So, does anyone have any suggestions where to start? I originally tried to accomplish this by fagging around with mod_rewrite, but I'd prefer a slightly more elegant way of doing things.