Here's the Neil Postman quote from Amusing Ourselves to Death that I felt was an apt discription of blogging, even though it was written 15-plus years before blogging was even invented:

...we have here a great loop of impotence: The news elicits from you a variety of opinions about which you can do nothing except to offer them as more news, about which you can do nothing.

Actually, the context of the quote is so excellent, that I'll include the whole thing in here (from pp. 68-69 of my copy--whatever version it is. I think it's a Penguin edition). This snippet says more in one paragraph than most entire books do:

For the first time in human history, people were faced with the problem of information glut, which means that simultaneously they were faced with the problem of a diminished social and political potency.

You may get a sense of what this means by asking yourself another series of questions: what steps do you plan to take to reduce the conflict in the Middle East? Or the rates of inflation, crime, and unemployment? What are your plans for preserving the environment or reducing the risk of nuclear war? What do you plan to do about NATO, OPEC, the CIA, affirmative action, and the monstrous treatment of the Baha'is in Iran? I shall take the liberty of answering for you. You plan to do nothing about them. You may, of course, cast a ballot for someone who claims to have some plans, as well as the power to act. But this you can do only once every two or four years by giving one hour of your time, hardly a satisfying means of expressing the broad range of opinions you hold. Voting, we might even say, is the next to last refuge of the politically impotent. The last refuge is, of course, giving your opinion to a pollster, who will get a version of it through a desiccated question, and then will submerge it in a Niagara of similar opinions, and convert them into--what else?--another piece of news. Thus, we have here a great loop of impotence: The news elicits from you a variety of opinions about which you can do nothing except to offer them as more news, about which you can do nothing.