Interesting takeaway from Macworld today:
Skyhook Wireless has driven around the US and Canada, mapping 23 million Wi-Fi hot spots to a GPS. Even if you're not connected to the hot spot, the beacon service knows which hot spots you're near, so when you use the Maps application on the iPod Touch or iPhone, you still get location data.
Neat, huh? Cool, huh? as Steve Jobs said.
Wireless is bidirectional.
You know what hot spots are near, and Skyhook's service can triangulate on that.
The hot spots know you're near. When you turn on your Wi-Fi enabled device, the grid knows where YOU are. All the time. As soon as that Wi-Fi laptop, iPod, iPhone, or other device powers on and starts looking for access points.
Food for thought.