This is responding to Patrick Holbrook's post -

Funny enough, I've done basically exactly what you're proposing and to much the same end last year…

I listed the wifi networks in a handout that I gave to people along the 'L' but I also made maps which I inserted into train cars that displayed the relative areas where WiFi networks were present in order to demonstrate the correlation of wireless networks with various parts of the city (wireless rich and poor).

http://www.amandawasielewski.com/wireless.html