It is easy to become unsettled by privacy-eroding aspects of awareness tools. But there is another — quite different — result of all this incessant updating: a culture of people who know much more about themselves. Many of the avid Twitterers, Flickrers and Facebook users I interviewed described an unexpected side-effect of constant self-disclosure. The act of stopping several times a day to observe what you're feeling or thinking can become, after weeks and weeks, a sort of philosophical act. It's like the Greek dictum to "know thyself," or the therapeutic concept of mindfulness. (Indeed, the question that floats eternally at the top of Twitter's Web site — "What are you doing?" — can come to seem existentially freighted. What are you doing?) Having an audience can make the self-reflection even more acute, since, as my interviewees noted, they're trying to describe their activities in a way that is not only accurate but also interesting to others: the status update as a literary form.