Re: Alternative to Facebook
Boone is correct. A distributed (sometimes also called decentralized) network is when data are kept in different places, places that each user (be that an individual, group, or company) controls. WPMU, Twitter, Facebook, etcetera control the users’ data and experience. Although the data may be spread throughout a series of servers or even distributed server clusters, the data is controlled by one authority and is often considered locked into a closed data silo–even if that data silo is hosted in the cloud.
For more details on distributed social networking (with a Semantic Web twist) see my article, A Flock of Twitters: Decentralized Semantic Microblogging.