Donncha, great work. I do agree with Michel though. I use three layers of anti-spam: the Math Comment Spam Protection plugin to stop the bots cold, the Simple Trackback Protection plugin to stop trackback spam, then Askimet to clean up what’s left. Works really well.

Without the trackback plugin, I get an extra 30 or 40 spam messages in Askimet each day, which makes it harder to pick false postives (a couple a week).

If you don’t like Captcha’s use the TanTanNoodles Simple Spam Filter instead of the math plugin. It catches comments where certain words or paterns are used and gets the user to confirm they want to post – this should stop bots which use naughty words without the need for a Captcha.