WordPress.org

Stops automated spam while remaining as unobtrusive as possible to regular commenters. The Spam Destroyer plugin is intended to be effortless to use, simply install and enjoy a spam free website :)

This version of the plugin does not work for user registrations, bbPress or BuddyPress, however there is an experimental version available which does. You can download the experimental version of the plugin from the Spam Destroyer page on geek.ryanhellyer.net. If you test it, I'd love to hear about the results.