Microsoft's Hohm lets people with participating energy providers track their energy usage online via a website. The end goal is to have the site give you tips on how to save energy and thus money.
The first participants are Pugent Sound Energy, Sacramento Municipal Utility District, Seattle City Light and Xcel energy. Not a huge amount of partners, but it's a start. You can ask for access to the project by going to the page and following the instructions.
At the very least, we have to give Microsoft points on the name. It's a lot more clever than Google PowerMeter, which does something similar (but is also limited to a few electric companies). [Hohm]