http://www.viewsflow.com/ is my thing--good explanation of what we are trying to do. I admit that we don't do a great job on the site right now--i am working on that as we speak.
The plan is this:
* watch thousands of people sharing content through Tw, Del, Fb, etc.
* build up an influence model--who is a good discriminator on stuff about China? Or about tech industry?
* present an aggregated view of what the 'top discriminators' recommend in each of the fields they are genuinely good at
* anyone can become an expert--based on how good your content recommendations are (as evaluated by our algorithms)
* make it bigger
the community stuff is teetering around--hasn't yet taken off. we have some ideas about how to make it take off, and am open for your suggestions.