I’m sorry, Disqus. The conversation you want to host is already happening, and it’s happening on Twitter.

For a long time, I thought LiveJournal was what blogging was meant to be: you had your friends; you had a customized RSS feed that told you what they were up to, and you had a commenting system that encouraged a community to form. LiveJournal is cozier than other publishing platforms, because the same users were commenting on your posts and writing the posts you commented on.

But what LiveJournal is missing is this: the conversation shouldn’t be leashed to a single post. How hard is it to keep a debate on one story going for a week, when the story keeps changing?

That’s why Twitter is such a great service. It lets a conversation flow naturally, and eddy around changes in the underlying story.

Right this second, one of the most popular topics on Twitter is Boxee. I could follow this conversation by jumping between two or three comment threads on half a dozen blogs — but Twitter is aggregating the entire conversation, and moving it off individual blog posts. So the news is news and the conversation is a conversation.

So why tumblr and twitter, instead of anything else? Because they’re as powerful as they have to be and as simple as they can be. Why try anything else?