But this isn't the first time technology like this has 'shrunk the world' and shone a light in dark places- In 1991 the news of Soviet coup d'état attempt was carried over IRC despite a media blackout in the country. Reports from the first Iraq war were carried over its channels as well.
And IRC is as old as the hills. In spite of that, It's always allowed for realtime group conversation -or- private one-to-one dialog. You don't need to create an account, big personal network, or audience of followers to start-up and jump into a conversation. You can monitor channels of topics and come and go as you please. It's a pretty damn efficient twitter, way before Twitter (and cell phones, text messages, even AIM for that matter)
What Twitter's done to the individual messages of SMS (and by extension, chat & IRC) is marry them to hosted nature of the world web web. Individual statements in 140 characters, published as html documents; those documents aggregated into user profiles & feeds.
With so many documents being broadcast and so little inherent organization to it's delivery, Twitter can be very much like being in crowded room where all your friends are shouting at themselves and each other. Third party software like Seesmic Desktop and Tweetdeck are powerful tools that help manage these twitter feeds like mini-email, but neither helps you discover the rest of twitter at random or topically, like you do on IRC.
Thankfully, developer Alex Bosworth has connected the dots and come up with something that marries the two. It's a proof-of-concept alpha called Tweetbe.at.
If you use twitter, you know that putting #hashtags in your messages is a way to tag or catagorize them. The idea behind Tweetbe.at is that #hashtags represent IRC channels of tweets. You need to log-in using your twitter account (not with password, but OAuth) and then you can visit or create and participate in as many channels as you want. If you like, It allows you to fold in other search terms and user's feeds so you can develop and refine the channel. The important thing, whether you want to moderate the channel or just sit back and watch, is that you can now surface more relevant tweets you may have otherwise missed, or use it to get into @reply conversations with new & interesting tweeps you otherwise may not have ever met!
Well done, @p1bx