I played around with X10 networking (device control using the in-house power wiring as a message bus) years ago, for home automation. Fun stuff, and usable even today. Recently, I've started working on an Arduino-driven thermostat replacement using XBees to get around the problem of running wiring in a house without any conduits (and not wanting to run plenum-rated cabling in the heating ducts). It's actually pretty…
I had lots of fun with X10 back in college, tricking out my apartment to have voice control over the lights and drapes. The X10 computer interface combined with Homeseer allowed me to create pretty complex "scenes" such as the always popular "seduce" command which would close the drapes, gradually dim the lights to 15% in 1% increments over a 1 hour interval, and start playing a playlist of mp3s that sadly started with Sarah Mclachlan and ended with Barry White.