What is Twitter?

If the purpose of blogs was to make it possible for people to easily publish paragraphs of journalistic or creative work, Twitter's purpose is to make it possible to publish sentences or even phrases. Twitter is essentially the world's largest almost-real-time Instant Messenger program, except that everyone, even people who aren't Twitter members, is part of the conversation.

Members get a basic profile page very similar to a message board. Then they can just post whatever is current in "threads" of only their own writings. Many of these posts consist of only a few words like "eating lunch now."

Is Twitter useful among the other Web 2.0 applications? It's probably not quite on the level of Writely or Netvibes, but as with all Web 2.0 ideas, it remains to be seen what users do with it. Most of the new many-to-many social web technologies are generating ideas just as unique as their own designs, and those ideas are coming from the user base first.