Linking multiple Arduinos using serial communications over a power bus.

I am new to Arduino, programming, and forums so please bear with me. My goal is to link multiple Arduinos together using the power bus with a serial control signal overlayed on it. I doubt the boards themselves have this capability but I though I could run the signal pin through a transistor and connect the collector to a DC-DC voltage multiplier to get an isolated five volts needed to boost the line voltage when the signal goes high. Is this something that can actually be done or would I be wasting my time trying to learn how to do the impossible?

I'm no expert, but see here: http://arduino.cc/forum/index.php/topic,21107.0.html

Also Google: "arduino signalling over power lines"

Warning: If you aren't particularly familiar with working with power you may damage things, including yourself.