Open Source clones
Microblogging vs. Blogging: 5 Ways to Create an Open Twitter Alternative Given the recent developments in the Twitter developer ecosystem, I think it's a good time to revisit the idea of an open Web alternative to Twitter. The fact is, the differences between microblogging and normal blogging are insignificant. I'm going to detail five of the differences. My point in doing so is to illustrate that the best way to bootstrap an open alternative to Twitter is not by inventing a bunch of new technologies or products. Instead, I want to show that most of the pieces already exist in the current blogging ecosystem.
Open Source Twitter Alternative StatusNet Releases iPhone App
Any.IO - Twitter and Identi.ca through finger or DNS.