I wrote a little script to fight comment SPAM much along the lines of Jay Allen's MTBlacklist filter (but for WordPress). This really simple script is compatible with all versions of WordPress and uses a powerful master blacklist from Reflective Reality. I would really like to get some people to try and install it and see how well it works. So if you are using WordPress and have been receiving some SPAM in your comments, please help me in testing this script. WordPress 1.0+ will even allow you to view the SPAM comments without them ever being displayed on your blog (using moderation) which would mean that if you do receive SPAM and the filter catches it, you will know that the script is working. Here is a link to WPBlacklist.
PS: Compatible with all versions of WordPress