This story about using Knod.es is pretty awesome. Knod.es (and SnapGoods) was co-founded by a friend and classmate of mine from Brown, so I'd heard about it, but I never really got it until I read this post. These use cases blew my mind. It's exactly what you wish you could do with your social network but couldn't if you were a mere mortal without a million Twitter followers. I will follow up w/ some of my own use cases once I get an invite code.