Defensio is a blog spam filter which claims: "Defensio improves accuracy: fewer spammy comments will get through to your blog and fewer real comments will be incorrectly blocked. Defensio makes managing spam a breeze: sorting through your quarantine is made simple through a smart ranking system and a condensed, efficient viewing mode. Our initial tests suggest that Defensio might just be the best thing since sliced bread." I installed it on my WordPress blog, which previously had SpamKarma and Akismet before that. I found that both allowed spam comments to be held in the moderation queue, which required me to check them. It's early days, but with Defensio I haven't had a spam comment either get through or be held for moderation. Join discussion...