Trackbacks spamming is one of the last big noise on the blogosphere and who regularly reads my blog already knows this (I've talked a lot in the last days about countermeasure I've adopted to stop it).
Brian Delahunty has developed an interesting Trackback SpamBlocker for .Text, a little modification to the engine that permits you to filter trackbacks spamming. The tool seems really good because it's really easy to install (it requires only a modification to the <configSections> section of the web.config file for your .Text and a replacement of the Dottext.Framework.dll file with the one provided) and it's totally customizable (you can add spam filters as you want because the Spam Blocker allows you to use regular expression to determine what is blocked and can work on both the title and the body of the trackbacks).
For the moment I've not installed it (because my SQL filter works really good) but maybe I'll try to add also this protection... 