Next time, if you want real help......... You might want to include:
What forum software are you running and what version?
After answering that question, there would be a ton more of them.
Also..... Unless it was SMF, why would you think Skuzzy could help you? I run vBulletin Version 4.0.1 and as smart a man as the Skuzzynator may be, I don't think I'd be asking him for any "pointers."
BUT............Like gyrene said..... Most forum software allows you to block IP's in bulk... But that can be very dangerous. So if a full IP was say 204.156.643.18 but the guy keeps coming back, you can try a partial like 204.156.643 or even 204.156 But the problem there becomes ALL ip's that start like that will be blocked.