Another technique to combat comment spam in your blog is to add some fields to your blog's comment form that cannot be seen. I am not talking about HIDDEN fields, although those might work in some cases (I have no idea how smart spambots are). A clever technique that I had not seen before in the above blog post sets the CSS style for these extra fields to invisibility. With a separate stylesheet,the common spambot might not ever realize that it is filling in a field that a human or other sentient would never see. You can just accumulate the comment spam in your database while hiding it from view (the approach taken above), but if you can modify your blog software, then comment spam can just be ignored before it makes it out to the database that is what I would do. In any case, another tactic to combat comment spam (and less annoying than some CAPCHTAs).