Here is a project that allows you to keep track of your household power consumption over a wireless connection. Jone’s energy monitor project counts electricity meter‘s indicator pulses, which the electrical distribution company uses to bill you. Once it reads 5 minutes worth of consumption data, it is broadcast to a web server over a XBee module.
Be advised that some power distribution companies don’t allow any electronics to be placed near or around their power meters.
Via the forum.