Too bad they don't. It makes app.net just another social network with lock in... I think Diaspora did right by making a full blown social network, because that is what is needed. The interface is clean and easy (at least as easy as the facebook interface) and creating an account on a so called pod is easy as pie. And setting up a server is for the ones who have time to spare or whose job it is. It is a bit like owncloud in that respect. You don't have to set up your own server in order to use it, but you could. As for a twitter clone, I don't think that would be viable. If you look at twitter, you see that most of the messages are just updates on someone's life. On facebook, you'll get the occasional creation of stuff (not in my network, but hey, it is possible) and the consequent loss of ownership over that data. The goal of the Diaspora project is freeing that data. I don't think that a twitter clone would have that effect.