I was looking at the NetStumber national access point map and noticing that it hasn't been updated in a while. Clearly the excitement of finding WiFi access points has worn off. But it started me thinking. What if there was a way to use that kind of data--the incomplete, potentially erroneous, volunteed-created--data, because there seems to be something interesting about knowing the GPS location of a given access point? I mean, access points don't tend to move and are broadcasting their IDs (in the form of their Ethernet addresses) all the time, regardless of whether you can log on to use the Net. How could that be useful?
It's useful in this way: until GPS hardware gets to be cheap enough to incorporate into everything as WiFi and Bluetooth are now, using Access Point/GPS location databases can create a cheap kind of GPS for WiFi devices. All that has to be done is that a table matching one with the other has to be downloaded to a device, and then when that device sees the Ethernet address appear, it knows (with some rough degree of certainty) where it is. Imagine a busy downtown area, such as the Financial District in San Francisco. There are dozens of visible WiFi access points per block. Sure you can only log into maybe 10% of them, but who cares if all you're looking for is their Ethernet address? Downtown SF is full of history: this giant area here was once the bay, here was where the Niantic Hotel used to stand, here's where that fire raged in 1906, etc. I can imagine creating a tour of downtown San Francisco that would fit on a WiFi-enabled PDA--something that's likely a whole lot more common than a GPS-enabled PDA--and would allow you to walk around downtown, giving you information for which the location was determined by the WiFi access points visible to the PDA.
Would it be super accurate? Of course not. But it would be cheap from a hardware standpoint--it would be expensive from a data-collection standpoint, but not ALL that expensive. One afternoon walking with NetStumbler would collect all of the necessary data, and it could be updated every six months, with the tour cues synched appropriately.
Sure it's a silly stopgap measure until actual geolocation becomes available, but I think that there's a whole lot more opportunity here than just downtown tours.