how do u get a mainspower plug through that tiny hole?
that sparkfun sensor can b integrated easier, i guess...
one just snaps it on the mains power line...
possibly u just measure the reactive power?
i have no idea how that sensor works, when there r 2 wires with the same current (just the direction is the oposite)...
i think u should wait for the high voltage experts... they should b here within a day... 