Library Science + Computer Science
The current social networks thinking is fascinating, and will only get better once more people dig into web services, and then the semantic web. It's a little disconcerting, embarrasing even, that no IAs are at the forefront of these discussions. Isn't that what we do, find interesting patterns in information and present them to people? It's high time we start balancing our focus on library science with some attention to computer science. Or better yet combining the two to result in information architecture designs that haven't been imagined yet.
When it comes to taxonomies/thesauri vs. ontologies as the organization scheme of the future, ontologies will win out because that's what the computer science people are using. They control the implementation and therefore innovation on the Internet. IAs will just keep using what software is offered to us, unless we reduce our navel gazing and get into the programmer's clubs. At least we can take encouragement in the fact that their interfaces still suck.
Kudos to Eric for outlining an implementation of social networks.