For multi-perspectives on Teaching Resources I could imagine something analogous to http://www.thesinglesjukebox.com/ with panels for different subject areas. This would be a candidate for the "curating" model - the site generates a list of the year's greatest hits. (This year's top song so far is quite rightly Janelle Monae..but note that one reviewer only gave it 4/10)
A curating committee needs to have a diversity of members: The Singles Jukebox produces scores for each song, but different reviewers sometimes vary wildly in their assessments, most importantly, explaining why. With social media, there's always a washback effect (think of it as a feedback loop) on users - so society needs to be very wary of systems where people just give "likes" or "retweets" without any criteria. The monopolar "like" button is just a way to automatically give prominence to the most simple-minded reactions.
Stephen Downes gave a presentation at the Canadian MoodleMoot and, after watching the recording, I wrote this post. In it, I reflect on the work he's been doing on groups vs networks for the last 12 years or so, and the mechanisms that best suit each of those.
I think that we need to encourage pro-social behaviours and to do that, people need 'skin in the game'. We can do that a number of ways, through badges, through reputation such as kudos, and through recommendation engines.
At the end of the day, I think we're going to have to try a few approaches and see what works in a Moodle context!
Probably the "tightly-knit and reasonably homogeneous group" is going to appear in moodlenet in the guise of the communities as seen in the design sprint prototype...
I think it's true that this sort of group/ community could score resources to their own satisfaction, and it would be a useful time-saver for people who share the values and criteria of the community in question. Saving time must be a common aspiration among teachers.
Clay Shirky was very good on how communities have their own vocabularies for dividing up their worlds. But this makes me think that networks are always in danger of coagulating into separate groups who rarely enter into a discussion with outsiders. That way users miss out on getting different perspectives on a given resource, instead they have to start out by deciding which community they feel at home in.