A journalist captured in Afghanistan told the world he was still alive by tweeting with a prison guard's cellphone.

This remarkable tale about a tweet kicks off a new meme here at Gadget Lab that we're calling Tweet of the Day, where we'll post our favorite tweets from just about anybody in our orbit: gadget customers, pundits, analysts, journalists, Silicon Valley bigwigs and so on. Each Tuesday and Thursday, we'll be handpicking tweets that we find especially fascinating, enlightening, hilarious, moving or sad — anything that really gets us buzzing.

Today's tweet comes from Kosuke Tsuneoka, a Japanese freelance journalist who was released from five months of captivity in Afghanistan over the weekend. Since he was captured April 1, no one had heard a single word from Tsuneoka, but on Sept. 3 he managed to send out a tweet: "i am still allive, but in jail."

Speaking at a press conference today in Tokyo, Tsuneoka recounted the story of how he managed to trick his captors into allowing him to tweet. A low-ranking soldier had just gotten a new cellphone, a Nokia N70, and was asking Tsuneoka how to use it.

The guard had heard of the internet but didn't know what it was, so Tsuneoka called customer care to activate the phone and configure it for internet access. He showed the guard how to perform a Google search of "Al Jazeera," and then he talked about Twitter.

"But if you are going to do anything, you should use Twitter," he said he told the guard. "They asked what that was. And I told them that if you write something on it, then you can reach many Japanese journalists. So they said, 'Try it.'"

And just like that, Tsuneoka was able to communicate to the world that he was still alive. This is a truly amazing story originally reported by IDG News that underscores the power of a web-connected gadget and social networking while telling us a bit about the disconnected culture of Afghanistan.

A hat tip to Mary H.K. Choi (@choitotheworld) for spotting and sharing this story.

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