The kids over at Facebook have decided to declare their fanboy-dom of stats and charts, especially the MRTG [img src="http://sale-online.click/wp-content/uploads/2008/04/technorati-chart.thumbnail.jpg" caption="" credit="" alt="technorati-chart.jpg"]descendants that are meant to track the buzz of what's going on in the world like Google Trends and Technorati's frequency charts.
Much like the ability to run ego searches on Technorati (or, I suppose, if you're into something more utilitarian than that, you can track news topics), it's a buzz tracking method that allows you to see what the wide world of Facebook is talking about in the various Facebook forums, and it's called the Facebook Lexicon.
It is a stats tracking system designed to find and aggregate mentions of searchable terms on Facebook users' profiles, groups and event Walls. They remove all personally identifiable information, and aggregate the data and chart it across the timeline.