Wrt my research on location-awareness, My Location is an interesting new google beta application that find people's location of people using its mobile mapping service (even if the phone isn't equipped with a GPS receiver). A feature available for most web-enabled mobile phones, including Java, BlackBerry, Windows Mobile, and Nokia/Symbian devices. What is interesting is the display of uncertainty (as a light blue circle) if you don't have a GPS-enabled phone around the blue dot (which corresponds to your GPS location). This uncertainty is claimed to be around one-quarter to three miles of a user's location. But advantages for this ranges from getting a location without GPS, draining less power than GPS.
This "My location" feature map the coordinates of the cell tower the cell phone is registered with. This way, Google taps in the large number of its mobile maps users who have GPS phones (not locked by the carriers) and it's a work-in progress process as described here:
"the database that identifies the location of a mobile phone is still under construction, so the service still sometimes draw a blank. The company expects to fill in the holes as more people use the service, Lee said. The tracking system's database currently spans more than 20 countries, including United States, much of Europe, Australia, New Zealand, the Russian Federation and Taiwan. It doesn't yet work in China or Japan."
Also have a look at NYT blog where the Google PR explains this a bit better:
"The story also talks about where “you are”. We don’t actually know who the person is or reliably where the phone is. We know that specific queries where the map is centered have come from a unique id number. Sometimes that map will be centered because that is where you are (centered yourself or by use of My Location), or it is centered because that is where you are thinking of going, or it is centered because you are curious about a location but have no intention of actually going there. From our logs, we are not able to distinguish these three very common use cases. Also, users have the ability to re-set the unique client id number as often as they would like. Finally, we do not know who “you” are and don’t have any way of finding out. There is no name, phone number, address, email or account login associated with this information."
It's also relevant to browse some of the blogs and the comments / reactions
Why do I blog this? interesting stuff about my research interests. That approach (although not very new) is quite interesting and it's intriguing to see how the interface reflects the different accuracy levels.