She's right... the X-10 modules are the most practical, and probably the most convenient. Alot of home security systems are the brains for the system (they are tied into a phone line or LAN line), they are tied into the electricity (wall plug), and then each x-10 module is assined an address through your security system (AC, oven, microwave, lights, stereo, tv's, EVEN YOUR BATH TUB!!!). You just talk to your system from a labtop, your PDA, your cellphone, you name it! Being that your security system is the brain, its highly password and firewall protected.
pretty rad stuff!
Apple is getting in to it with there wireless wi-fi as well (using the ground wire to send data to areas in your house - like audio to the stereo in the other room from your i-tunes.
The question is... How silly do you want to go?!?