Today I saw a few posts that mentioned Akismet. This is a service to help stop blog comment and trackback spams. The contents of each comment is sent to Akismet's servers in an HTTP POST request and then the response is whether Akismet considers the comment spam.
Akismet started out as a WordPress plugin, and it has been ported to several other blogging systems. I have ported it to LifeType. This was pretty easy, especially with Bret Kuhns' Akismet php class.
I am interested to see how well it does. From the reports, people a pretty happy with the results. I have enable this, and disabled the captcha plugin to truly test the plugin.