I'm looking to put thermometers in several rooms, reporting back to the central controller. So... anybody know of any off-the-shelf solutions that don't involve running new wires? The closest thing I've found is weather stations with PC interfaces and a remote sensor, which are (a) expensive, and (b) give me only a single extra sensor. Something I could put in a junction box and power from the house 110 would be great.
Ideal would be an INSTEON module, since I'm using that for everything else. Second choice would wi-fi, since that's the other network I've got in the house.
At the moment, my best bet is looking like building something with an XBee radio module, which just seems ridiculous. Somebody must have done this before!