Have you shared this particular treewalker? I wouldn't mind having an already developed bit of code for this in case I start using the idea when I build a webapp this summer for myself (where bending the rules for demonstration is much easier to pull off than at the office ;) )

direct urls:

http://preview.rrauction.com/content/images/scans/3223/3223557_1.jpg

http://preview.rrauction.com/content/images/scans/3223/3223557_2.jpg <-- note it just shows the rear of the card

Of course I know that every meter is absolutely positioned, I didn't mean that they needed to look all around when they got there, I meant that you only needed a few men on staff to do site visits as a normal course of action. Which costs more, 30 meter readers on staff or 3 "inspectors"?

And you have to admit most smart meters don't know their actual location on their own, it's the coordinating central office computers that store that information. Yes sure, some models may have that as a feature/benefit, but it's not a requirement.

As for which uses more energy, I would have to do the math and I've not yet had my coffee, but at a few partial-amps per device it would take quite a few homes to equal the cost of one truck. Plus, power plants have more efficient means of energy extraction than a truck does so I don't know what those conversion factors look like.