I fired up Google Maps in Chrome on my Mac Book Pro running Windows 7. To my astonishment, when I right clicked on an intersection and selected
Directions To Here, it filled in My Location automatically in the A field. And it was ridiculously accurate too.
Typically, I wouldn't be surprised - I've heard that there are databases of WiFi SSIDs out there. However, I just moved yesterday and plugged in my router this morning (12 hours ago). As far as I know Mac Book Pro does not contain a GPS. It is unlikely that a Google truck drove by my house in the last 12 hours and its data made it into the Google Maps database that quickly.
So, how did Google Maps determine my location?
P.S. I tried the same thing in IE and Google Maps said that it could not find the exact location, but could use the
rough location. Which was also really close to my location (but across the street).