Not too long ago, I register myself for an account for identi.ca.
Which is an open source alternative to twitter. I stop using it for a while, which is really like not long ago. For the reason that, it can't really integrate with facebook, or other webservice.
Now it is really different. For one, it can post to twitter, which really means a lot of their limitation is gone. So it can post to facebook through twitter. And other service. But not quite posting from the otherway round. So i can't really track, my friends from twitter here.
Here's the interesting part, the features taken out from twitter is in here. So the xmpp posting is in identi.ca, so we can post using gtalk, and track status using identiSpy, or any xmpp client.
The interesting part about this whole thing is, it is open source, so the software can be installed and modified on our server. Which it self really interesting.
Feature wise, I think we have a winner, but will it replace twitter, I don't think so. For one, too many people using twitter already. But it will interesting to see whether, identi.ca is more reliable than twitter.