This is a bit of self-promotion, but hopefully it can help someone with a website and spam issues.
My forum got a load of spammers not long ago. So I made an Apache server log spam analyzer that will analyze your server log and check the most frequent visitors (ips) against a spammer blacklist. You can then use this information to block bad IPs via your .htaccess. I figured it would help me in the future and it could help others as well, so you should be able to upload it anywhere and run it.
I set it up as a GitHub project if you're interested in the code or would like to contribute to the project.
https://github.com/RWenger/Log-Spam-Checker
To get the spam analyzer and read more, check out the thread for it at http://www.technofyed.com/showthread.php?tid=5928 (disclamer: my site).
If you use it and would like to see more features, let me know here or on the thread linked above.