Just ran across a great tutorial on how to use the Pingback module for Drupal.
I've been a little bit out of the latest tools for blogging & social media lately, and Pingback as a replacement for Trackback is a really good idea. Basically, it's Trackback with a vengeance: it forces that the site placing the pingback actually link to the article in question, and places limits on the number of links available on the destination pingback. Pretty sweet!
Ultimately, controlling spam while publicizing a site is one of the great challenges of running a long-standing blog. The spammers attack, and attack, and attack, wearing you down. I plan to implement this pingback utility just as soon as I get the spare time to update my Drupal install, too.