Nicholas Carr, in The Atlantic:

As the media theorist Marshall McLuhan pointed out in the 1960s, media are not just passive channels of information. They supply the stuff of thought, but they also shape the process of thought. And what the Net seems to be doing is chipping away my capacity for concentration and contemplation…. Thanks to the ubiquity of text on the Internet, not to mention the popularity of text-messaging on cell phones, we may well be reading more today than we did in the 1970s or 1980s, when television was our medium of choice. But it’s a different kind of reading, and behind it lies a different kind of thinking–perhaps even a new sense of the self.

The article includes an interesting anecdote about Nietzsche and his typewriter, and also offers a clever interpretation of the death of HAL from 2001.