What's "twitter"?

[DMiller]

But how is it a network any more than a blog is?

I just don't see that. It's exactly the same as a blog from what you've described, no functional difference except for the imposed length limit (which can easily be self-imposed, so I don't see the point there either).

It's the connections you make with people. A blog is much more of a one-way conversation, although there usually is a comment system. Twitter is making short comments about what you are working on that others can respond to, and you can respond to the comments of others.