I just completed the Tweet-a-Watt project and I am hooked. I have had EnergyLogger running and even patched my results over to Pachube. The next thing I was thinking of was taking my Oregon Scientific (Model EMR201) wireless thermometer. It is super simple: Indoor Temp, Outdoor Temp, and an Ice Sensor. How hard would it be to assemble an Adafruit Xbee adapter and piggy back just like the Kill-a-Watt. Has anyone done this before?