This article from MIT has lots of good information about power scavenging, including a survey of piezo buttons, one of which powers up a transmitter and sends data. This would make a nice aiosphere device, I think: a button you can stick anywhere in your house, and it does whatever you want it to. Maybe you can label it? True to the principle of the aiosphere, the button doesn’t need to be programmed, or have any ‘understanding’ of its purpose: that is all established by the server, or the receiving device.
Maybe a super-fancy version uses e-ink to label itself (zero static power).

All the rage, I know. Hate to bandwagon. But it is a fact that the aiosphere system would reduce a whole lot of power use in an average ‘wired’ home, by allowing tiny, extremely efficient devices to do much of the work that multiple laptops and desktop computers do in a lot of homes and offices.

What about a line-powered socket device which measures and transmits power useage to the aiosphere? One of these in each socket could create a power map for the home, allowing users to see graphically where there biggest consumption is, and improve it. I could even see something that is a standard part of every socket.

Someone has probably already made such a thing, a replacement dual outlet with built-in zigbee power monitoring. The data vis side of it would be very interesting too. If this hasn’t been done yet, it would be a compelling product. But of course it has, many times:

http://www.plogg.co.uk/index.html
http://www.zigbee.org/imwp/idms/popups/pop_download.asp?contentID=12361
http://www.springerlink.com/content/thn805636348/?p=237ddf1ff7524538b310341e6cc11853?=0

Lots of fascinating developments out there. A very exciting field indeed. I wonder how my dirt-simple system could directly contribute? I guess I could make a socket gizmo which can measure energy useage and report it. I wonder how cheap this could be? Probably not cheap enough to pay off. Besides, the vision is a system which is self-correcting.

Is there any value to the very early, rudimentary system I am thinking of, which only visualizes for dumb appliances? I think it may still be worth doing. The challenge there is figuring out what can be done with the information, given that devices are all dumb. How cheap would a device have to be, in order for the system to be profitable? I guess that depends on how much waste there is in your home that can be corrected. So, once you have a web visualization, what do you do with it? Turn stuff off, I guess. Something smarter?

Certainly even the most rudimentary implementation gets a good deal of attention in today’s climate (sorry for the pun):
http://www.core77.com/competitions/greenergadgets/projects/4621/

This is how the serious players do it:
http://www.tendrilinc.com

Could I make a simple device that includes the relay too?  Probably very hard to get UL approval.  I need to stay away from issues like that.  Still, would be intersting.  Open source hardware, do it yourself green, involving the community in developing new green techniques, etc.  The relay is a nice idea to close the loop, if the user could then set timers etc. for individual outlets, like TV or computer in standby.