Sustainopedia, or useful microcontributions

I was filling out a survey for Grist and found myself writing the following in the comments section:

In question #6, you pose the following for people to respond to: “Passively reading is so 20th century; Grist should publish content I can interact with (comment on it, vote in polls, rank its value, etc.).” I said I was neutral about this, but I want to explain. Of course there is great opportunity with getting user involvement (Web 2.0 and all that), but I think just another place where users can post comments is not what the world needs. I would LOVE for you to be the hub of a system that accrued the knowledge of your readers over time. Something that either built up profiles of products (based on opinion and or hard fact) that could then be used by people browsing (or by systems on the web) to help people make purchasing decisions OR otherwise collected environmental info (Sustainopedia?) in at least a narrative form, but ideally in a (however flawed) structured format (or semi-structured, such as RDF [see Semantic Web]) that would then become a resource for our culture. So, I guess I REALLY would like you to publish content I can interact with, but I don’t just want another place where the sea of opinion never amounts to much. I want you to provide the structure for people to make something cool that gives back to the world.