I'm completely fascinated by Twitter right now--in much the same way I was by blogging four years ago, and by ICQ years before that.
If you haven't tried it yet, Twitter is a site that allows you to post one-line messages about what you're currently doing--via the web interface, IM, or SMS. You can limit who sees the messages to people you've explicitly added to your friends list, or you can make the messages public. (My Twitter posts are private, but my friend Joi's are public.)
What Twitter does, in a simple and brilliant way, is to merge a number of interesting trends in social software usage--personal blogging, lightweight presence indicators, and IM status messages--into a fascinating blend of ephemerality and permanence, public and private.
The big "P" word in technology these days is "participatory." But I'm increasingly convinced that a more important "P" word is "presence." In a world where we're seldom able to spend significant amounts of time with the people we care about (due not only to geographic dispersion, but also the realities of daily work and school commitments), having a mobile, lightweight method for both keeping people updated on what you're doing and staying aware of what others are doing is powerful.
I've experimented a bit with a visual form of this lightweight presence indication, through cameraphone photos taken while traveling. A photo of a boarding gate sign, or of a hotel entrance, conveys where I am and what I'm doing quickly and easily. But that only works if people are near a computer and are watching my Flickr photo feed, and that's a lot to ask.
I also use IM status messages to broadcast what I'm doing. My iChat has a stack of custom messages that I've saved for re-use, from "packing" and "at the airpot" to "breaking up sibling squabbles" and "grading...the horror! the horror!" But status messages have no permanence to them, and require some degree of synchronicity--people have to be logged into IM, and looking at status messages, while I'm there. Because Twitter archives your messages on the web (and can send them as SMS that you can check at any time), that requirement for synchronous connections goes away.
Blogs allow this kind of archived update, of course--but they're not lightweight. Where one might easily post a Twitter message along the lines of "on my way to work", a blog post like that wouldn't be worth the effort and overhead.
I've heard two kinds of criticisms of Twitter already.
The first criticizes the triviality of the content. But asking "who really cares about that kind of mindless trivia about your day" misses the whole point of presence. This isn't about conveying complex theory--it's about letting the people in your distributed network of family and friends have some sense of where you are and what you're doing. And we crave this, I think. When I travel, the first thing I ask the kids on the phone when I call home is "what are you doing?" Not because I really care that much about the show on TV, or the homework they're working on, but because I care about the rhythms and activities of their days. No, most people don't care that I'm sitting in the airport at DCA, or watching a TV show with my husband. But the people who miss being able to share in day-to-day activity with me--family and close friends--do care.
The second type of criticism is that the last thing we need is more interruptions in our already discontinuous and partially attentive connected worlds. What's interesting to me about Twitter, though, is that it actually reduces my craving to surf the web, ping people via IM, and cruise Facebook. I can keep a Twitter IM window open in the background, and check it occasionally just to see what people are up to. There's no obligation to respond, which I typically feel when updates come from individuals via IM or email. Or I can just check my text messages or the web site when I feel like getting a big picture of what my friends are up to.
Which then leads to one of the aspects of Twitter that I find most fascinating--exploring clusters of loosely related people by looking at the updates from their friends. There are stories told in between updates. Who's at a conference, and do they know each other? Who's on the road, and who's at home. Narratives that wind around and between the updates and the people, that show connections. Updates that echo each other, or even directly respond to another Twitter post.
There's more to it than that, but I'm still sorting it all out in my head. Just wanted to post an early-warning signal that I see something important happening here, something worth paying (more than partial) attention to.