[stephengillie]

We can track people, cool! And probably kids too! What about dogs and cats? Rats, mice, and cockroaches?

What's the range on this technology, and what happens if we move the router around with us? Maybe we take it to a new building and plug it in there? Or maybe we can use the wifi modules on phones to do this also? It sounds like a great scanning device. And how long before we can also see huge chunks of metal or strong magnets with this technology, based on how radio waves interact with them?

[aidenn0]

6cm is the wavelength at 5GHz and most sensing devices have issues with sub-wavelength objects. If you're paranoid you can hang a bunch of strips of aluminum foil that are 3cm long all around your house, which could confuse the sensor. (see http://en.wikipedia.org/wiki/Chaff_(countermeasure))

[theoj]

Work is underway on 60Ghz Wifi, which has wavelengths of only a few millimeters.

http://www.pcworld.com/article/2030041/meet-60ghz-wi-fi-the-...

In a few years we could have tri-band routers covering 2.4Ghz, 5Ghz and 60Ghz. Correlating the info from all these frequencies should provide a much better picture.