Ironic note: My digital camera uses the same technology utilized by me in 2003 to get me in a world of federal trouble (okay, so that was not specifically the overt act that landed me in hot water, using the internet connection I found was). It uses it to put a latitude/longitude coordinate on the images I take so I can see where they were taken. How was that data collected to have that work? Dorks driving around with laptops, wifi cards, and GPS units.
What was villified in the news in 2003, 2004 and 2005 is now status quo. My iPod Touch also uses that technology in order to emulate a GPS in location based apps such as foursquare and google maps.
Consider me to be so far out on the cutting edge, I was actually cut.
(and before someone accuses me of being late to that party, I should note that prior to acquiring a proper wifi card, we were doing netstumbling like exercises with Spectrum24 and RangeLan2. This was in 2001/2002 era)