Tweet, tweet

Culture | Simplicity and functionality are making Twitter fly | Mark Bergin

Graphic: San Jose Mercury News

Two years ago, a few savvy web developers posed a question to the world: What are you doing?

Turns out, that innocuous opener for all manner of human interaction is tough to ignore. People numbering in the millions have since logged on to twitter.com to post answers and read those of friends, family, or whomever else they may find compelling. (Like Google, Twitter knew it had struck a chord when it went from being only a noun to being also a verb.)

James Karl Buck, a graduate student from the University of California-Berkeley, joined the cultural phenomenon this past spring—and not a moment too soon. A week after opening an account on the site, he and a translator were arrested in Mahalla, Egypt, as they sought to cover an anti-government protest. On the way to the police station, Buck connected to Twitter via his cell phone and fired off a single-word distress signal: "Arrested."