Tagging Second Life
Tags have proved one of the most powerful Web 2.0 ideas. They let everyone add their pebble to the cairn of taxonomy, creating a rich tapestry of knowledge that would be impossible to match using automated means (well, with the current state of AI, at least).
Tags are a kind of signpost in semantic space, so an obvious extension would be to tag other kinds of space - for example, the virtual one of Second Life. Enter the LandRing, which lets you do exactly that. It's another product of the fertile mind of Timeless Prototype, and it's being made available through the Multi Gadget - here are the details.