Twitter -- the global chat service beloved by geeks and 'social media' fans -- often gets a somewhat deserved rap for being shallow, filled mostly with people's thoughts about the weather or what they had for breakfast. But every now and then something important happens, like an earthquake or a forest fire, and the service shows its true potential.

The most recent example was the Twitter stream from a Chinese "citizen journalist" or blogger named Zhou "Zhuola" Shuguang, who got a visit from some government officials after he showed up in Beijing to blog about the Olympics. They said they were there to talk with him about a breach of the government's "one child only" rule (which is more than a little odd, considering Zhou is childless), but it became obvious that what they really wanted was for him to leave Beijing.

Global Voices, the excellent global blogging project founded by Rebecca MacKinnon and the Harvard Berkman Center for the Internet and Society, caught wind of the detainment and started posting translations of Zhou's Twitter messages, updating the post with each new message as it came in.

Not only did several  officials put Zhou in a car and drive him back to his hometown, but others also apparently went to visit his parents, saying they wanted to take them out for tea (one of the officials who detained Zhou was an executive with the Changsha Mining Group, the company that Zhou's father worked for). In his last update the blogger said that he was unharmed, and that he was planning to return to Beijing accompanied by a journalist, in defiance of the authorities.

A fascinating story -- or at least the core of a fascinating story -- and all told entirely via Twitter. The "first draft of history" indeed.