I’ve just released Trackback Keyword Plugin. It’s a Blojsom plugin that checks the content of trackback URL for the existence of at least one of the specified keywords which will determine whether the trackback is a spam or not. A trackback spam will then be deleted or moderated.
I created this plugin because my blog started receiving some trackback spams from the usual poker-viagra-and-friends web sites. I know this plugin is not a perfect solution, specially compared to Akismet. However, having another option for spam fighting is not a bad thing.