diaspora*
A privacy-aware, distributed, open source social network
...Unlike some networks, you don’t have to use your real identity. You can interact with people in whatever way you choose. The only limit is your imagination. diaspora* is also Free Software, giving you liberty over how you use it. In diaspora* you own your data. You don’t sign over rights to a corporation or other interest who could use it. In addition, you choose who sees what you share, using Aspects. With diaspora*, your friends, your habits, and your content is your business, not ours!