I did a search for this and didn't see any references to it, so if it exists already a.) I haven't seen it and b.) I didn't know it existed. Apologies if it's not new. I'm sure you'll let me know if it's a bad idea. ;)

This is an electromagnetic (EM) or radio frequency (RF) map of residential areas. The EM spectrum would be divided up into frequency bands, each one assigned a color. Trucks containing EM-RF field strength detecting equipment would roam around residential areas taking measurements at pre-determined locations. Data would be compiled into maps, each one a certain frequency band with at least "X" field strength. Many maps would be needed to cover the higher-freq end of the spectrum, but taken together you would have a good idea of the amount of RF coming your way. This may or may not help you sleep better at night.

Taken a step further, a picture of the changing RF landscape around your neighborhood could be captured over time.
-- Gamma48, May 02 2007

random, halfbakery