I'm interested in this kind of product, but I live in an apartment and don't have access to my electric meter (or if I do, I definitely can't install things on it). Is there something like this I could use on individual outlets?
Depending on what state you live in, your apartment building is required to give you access to the meter that measures your apartment (to verify that you're getting charged correctly). If you ask nicely you might be able to convince your landlord to let you hang one of these (especially if the meter is indoors). I proposed such a thing to my landlord and they were interested in knowing more.