Found the following from Dvorak Uncensored:
Most people who run blogs have issues with comment spam in their blogs and there are all sorts of fixes. Marc Perkel at ctyme.com – my host — was floored, he said, when he realized a simple command to the Apache software would kill most of it — and it does indeed work!
Here is the short code running on the ctyme server for my dvorak.org using WordPress-based blogging software. Altering it for other blog software and other blogs should be simple for anyone running Apache.
<location /blog/wp-comments-newpost.php> RewriteEngine On RewriteCond %{HTTP_REFERER} !^.*dvorak.org/.* RewriteRule ^.* http://www.ctyme.com/comment-spam.html </location>Essentially it makes the basic condition for any post rigid: it has to be coming from a link within the blog itself, the “comment” link. Most spam does not.
My spam count on the blog has dropped from 50-100 to 2 per day without any other tricks.
