If you’ve been part of this whole Internet thing for a bit, you’ve probably heard and/or seen Google’s Zeitgeist which provides an interesting snapshot of the culture based on the searching trends.
I ran across something similar called twistori. It follows all the Twitter traffic, matches based on some simple emotional keywords (e.g., love, hate, think, believe, etc.) and displays it in a nice scrolling display. I ran across it a few days ago and have been enjoying dropping in and watching it for a minute or two.