I've never bought the idea of "passive participant" as synonymous to "lurker". It's one thing to watch for awhile to learn the norms of a community, or to decide if it's for you, before jumping in (what Wenger calls "legitimate peripheral participation"), but at some point it becomes just eavesdropping, and, worse, taking without giving back. In my view real lurking has no element of participation. (And as I recently Tweeted, "everyone loves a lurker until they're stuck on a grad school project team with one". ) We need better terminology for that. I DO hope, though, that the evolution of social tools -- and I see a lot of promise here for Pinterest -- will bring the change you describe for those who want to join in. Best, Jane