The Computer Security Lab at Rice just released the first public version of the Trackback Validator plugin for WordPress blogs. Since Iâ€™ve been using it, Iâ€™ve had 100% classification accuracy on Trackbacks (read: every legit Trackback makes it through, not a single spam Trackback). Maybe Trackback isnâ€™t quite so dead after all.
The system checks to make sure that the URL of the trackback links to your page. This reminds me a lot of Sam Ruby’s feedback mechanism. As a bonus, there’s a great use of sparklines in the plugin page.