I am working on something, as well. I currently use a Linux server centrally and an Arduino for prototyping the various sensors I want. One thing I'm starting

I am working on something, as well. I currently use a Linux server centrally and an Arduino for prototyping the various sensors I want. One thing I'm starting on right now are door sensors. Anyone found/devised a small, battery-based wireless door sensor? Ideally, I'd like a year or more battery life. I can't run wires to every door in the house, so I'm thinking of some small wireless sensor with a reed switch that sits in power off mode when the door is shut, but flips on when the door is open and wirelessly (Xbee?)sends a UID to the central controller.