Nonpartisan Social Network - Continued (Idea)
In fact, why stop there? You could imagine similar needs for blog posts and all sorts of other structured data. Maybe a basic distrubuted triple-store server, with various plugins (written in scripting languages - python, ruby, perl) to handle specific types of data (FOAF, etc.).
You could do very similar things using SPARQL update, but I think that having a server with plugins (as mentioned above) would make it much easier to build domain languages for different business objects. This would allow a greater level of abstraction for developers, which would speed up adoption as it would be both useful and trustworthy/open/transparent.