Clay Shirky, quoted below, provided a great perspective to the NY Times on the discourse of blogs, noting how people can use them to inform one another or not. I have observed that in any online discussion, convergence is a struggle where people have to be committed to listening to each other. In this NY Times article (registration required, free for only a few days), John Schwartz does a great job of showing the competing forces.

Link: The New York Times > International > International Special > Communications: Myths Run Wild in Blog Tsunami Debate.

the key to reasonable discussion [is] to get beyond flames and the "echo chamber" effect of like-minded people simply reinforcing the opinions of one another and to let the self-correcting mechanisms do their job in a civil way. "You hope the echo chamber effect and the fact-checking effect will balance out into a better and more nuanced set of narratives, and a more rigorously checked set of facts," he said. But in such a sharply contentious world, "The risk is it will largely divide itself into competing narratives where what even constitutes a fact is different in different camps."