Over the past few days, we’ve heard reports of how the post-election demonstrators in Iran have been using Twitter as a means for organizing protests, moving crowds from neighborhood to neighborhood to keep one step ahead of the armed authorities … and to upload images and video clips of the demonstrations to broadcast to the rest of the world. Twitter has played an important (and successful) role in engineering a “grand workaround” scheme, thwarting a government-ordered news blackout.

We saw the same phenomenon play out in the Eastern European country of Moldova just a few months back.

Viewed from this perspective, Twitter seems to be living up to its billing — in spades.

But there’s also research that shows another side of the coin. A just-completed Harvard University study of 300,000 Twitter users has found a classic rule of behavior in force: just 10% of users are generating more than 90% of the content on Twitter.

It goes even further than that. The average Twitter user “tweets” about once every 75 days … or even less frequently. And the median number of tweets made per person is … One!

That’s right. More than half of the 300,000 people in the Harvard study have sent just one tweet ever. It was with dry understatement that Bill Heil, the Harvard Business School graduate who carried out the study, reported, “Based on the numbers, Twitter is certainly not a service where everyone who has seen it has instantly loved it.”

I have an additional explanation to offer: Perhaps most people haven’t (yet) figured out what to do with Twitter to make it meaningful in their lives.

It didn’t help that Twitter itself set the bar at a pretty low level right from the start by suggesting that users answer the question: “What are you doing?” How inconsequential is that?

As it turns out, the trivial isn’t where Twitter has found its true voice.

Indeed, ask the Iranians or Moldovans whether Twitter has been meaningful in their lives. You’ll get a life-and-death answer in the affirmative.