I’ve always like Akismet as a spam protection on this blog, but the last few weeks I had to trash at least 5 comments per day. Since I couldn’t be bothered with that any more, I tried out “Math Comment Spam Protection".
Math Comment Spam Protection asks the visitor making the comment to answer a simple math question. This is intended to prove that the visitor is a human being and not a spam robot.
Example of such question: Sum of 9 + 9 ?
So far: I’ve not had a single spam comment and only the positive ones seem to get through (or some of them still get dropped and I wouldn’t know about it). So if you’re tired of spam comments, give that plugin a try.