Announced at CES 2010, this is a wifi enabled device that sits between a house appliance and the wall socket. It has a small linux based OS and web site so you can access each device via a web interface.
It can monitor the energy use as well as control the device so it does a lot. Sadly, it it said to cost about $80 each.
TOO Expensive. Seems like a low tech Kill-a-Watt ($20) and a spreadsheet would still be more efficient.