I've thought about doing this, but instead of being random I thought it'd make more sense to mimic my habits. So turn on the living room lights from sunset to 10pm, turn on bedroom lights from 10pm until 10:30 etc.
I find my network is more reliable by adding a FilterLinc to anywhere I have a wall-wart plugged in.
http://www.smarthome.com/1626.html
There are a few exceptions to this of course like Cell phones etc, but in my house about 5 of these really made a big difference.