if every WRT in town were feeding its 'wl scanresults' and every metrix box its 'iwlist ath0 scanning' into a database, a realtime AP database would be keep up to date automatically.
part 2) then every AP would have to know its GPS coordinates. which means it would have a rough estimate of the coordinates of other APs. it could alert someone if an AP's lat/long didn't make sense or was probably inaccurate. using the same not-too-accurate triangulation you could provide rough locations to network clients!
we've just created a GPS-like system that is land-station-based and works indoors and everywhere you're within range of the cloud. hmm. doesnt aircraft already have LORAN or something that is the same idea? one form of location via hotspots is patented.