I was recently at Purdue University to teach a graduate seminar at the CERIAS center for information assurance and security - http://www.cerias.purdue.edu/ - hosted by Gene Spafford and Victor Raskin, two lively and hospitable gents. Another professor had recently returned from a meeting at which researchers presented a paper about their company, a television, internet, and media ratings tracker, and she told me that the company monitors not only public web sites related to their work, the ones you would expect them to track, but also sixty million blogs in real time.

Sixty million blogs in real time. They mine the text of sixty million blogs ... looking for trends ... in real time ...