This one is really neat:
The Annotated New York Times tracks blog postings that cite articles published by The New York Times. These blog fragments are grouped by author or by topic to form virtual, distributed conversations that span multiple sites and that center around the coverage of news events as reported by the Times.
And this is not all. They
offer over 6,000 feeds tracking NY Times topics, authors and blog commentary. The list makes me almost feel dizzy.