Your IP address is, of course, already known by every site you visit, for example:
http://whatismyipaddress.com/
And, as that site shows, the IP address can be narrowed down to location depending on how much info the ISP releases.
The war driving info can be MUCH more accurate as far as actual location since directional antennas can be (are often) used as the drivers drive around. However, looking at the map on that wigle.net site you'll see a massive concentration of nodes along (right on top of) major roads - that's simply because the war drivers were collecting data while driving on those roads and the non-directional strength of the detected routers only supplied them with "somewhere around here" information.
BTW - when I look at the maps I do NOT see my own network - that easily could be because I'm a quarter to half mile from any major road so the network transmissions simply weren't detected. My own network does not advertise SSID and uses WAP encryption, but there exists lots of software that could find it automatically anyway if the war driver is running it.
BTW, part II - my =TV= uses wireless as well - I have NO idea what sort of info IT is putting out there nor if it can serve as an access point, for example. So that could be a wide hole my own network.
BTW, part III - and, of course, the Wii and DSes around this house also are wirelessly on the network so they, too, could be holes.