I just came across BlogPulse which is a blogdex, but you can also graph the frequency of topics in blog posts (they call it trending). Essentially, you can track pop culture. I love the information age - I would never have thought something like this could be done even 5 years ago. I tested it with many different topics, and the one that seemed most popular was Harry Potter, topping out at a whopping 5 percent of all posts around the release of the sixth book. Talk about culture saturation! And apparently, HP is popular among inmates at Guantanomo (sp?) along with Agatha Christie (huh?). Somehow they seem a lot less threatening now...Hmmm, Stan Shunpike....