Akismet.com
I’m really happy that Ozh recommended Akismet.com to me. It’s a comment spam catcher for Wordpress. For the past couple months I’ve been getting more and more comment spam every day — the kind that looks like it was sent by a real person and doesn’t use any of the comment blacklisted words.
Akismet caught 26 for me in the last 24 hours. Zero false positives. If you aren’t using Akismet yet, all you need to do is sign up to Wordpress.com.