Someone Get Hilary Rosen a Drink

Justin Frankel, the man responsible for WinAmp, Gnutella, and plenty of other stuff that's probably sitting in your hard drive, recently released Waste. The program makes it easy to create small, secure networks using public key encryption. Right now, it's primarily a chat client for tiny groups of friends who know each other, but it seems as though with tweaking it could be the mother of all p2p clients.