Place Lab is software providing low-cost, easy-to-use device positioning for location-enhanced computing applications.
Looks like they got this thing all wrapped up. ;) but really, looks like a pretty cool start. Now if I can just figure out how to run these silly java apps.
They also use wigle.net, which is Wireless Geographic Logging Engine, Plotting WiFi on Maps. This looks like a really cool resource for wifi maps around the U.S. Not sure about abroad yet, I'll have to dig around some more. hrm, again, I wonder if there is a feed or something someone could grab and use in the SpyTrack Geo-Aggregator (need a better name).