Of course we are familiar with Google using "authority" to depict a site which is considered authoritative on a subject as a result of other people (sites) linking to it, which are on-topic, and age of domain and a few other bits and bobs. It is not a bad method though very very flawed. Of course 90% of surfers don't move pass the "authority" so it becomes ummm important.

This method of course could not be used for twitter as there is no such aggregation or measuring other than numbers of followers or updates, @replies.

There is though significant posting of data and human preferences that should someone clever be able to "harness it (hehe) they'd open a gold mine (ignoring privacy concerns that is).