There's a product called the Efergy True Power meter that does exactly that. It measures mains electricity, wirelessly reports to a central server and shows yo

There's a product called the Efergy True Power meter that does exactly that. It measures mains electricity, wirelessly reports to a central server and shows you real time and historical graphs of energy usage at sub-minute resolution. http://efergy.com/us/elite-true-power-meter http://efergy.com/us/elite-true-power-meter