Sounds like a decent explaination..... (Re:jraef)
Surfinsparky, X-10 is a power line carrier protocal used for a type of automation for dimmers and switching that was popular once. Although it has bee around for some time, it still continues to develope. (Rather slowly) By inserting some data (noise) on the line signals can be sent from on device to another. In the case I mentioned items in two different homes had the same address. With no filter between them, if the guy nextdoor turned on his living room light, the light of the customer would turn on.
http://www.smarthome.com/remote_entire_home.html
