I had never seen or heard about PubSub before. I first saw it over at
bryght.com where they have integrated it with Drupal.
Integrating PubSub, MyYahoo or any other automated RSS generation service into CMS aggregators such as Drupal is a powerful combination.
The degree to which it has become possible for individuals to automate the process of extracting precise bits of information from the overwhelming and growing mass of data flowing across the planet is really amazing .
In fact, I found Bryght by using Google to look for sites linking to my site. Apparently, some of my blogs had been aggregated by PubSub (probably using the term "Drupal"), included in the Bryght's PubSub page and cached by Google.