A new method of computer-based tracking has recently emerged: wifi. A company has been sending trucks all over the U.S. and Canada mapping access points, addresses and names, and now claims that they have technology to say where you are in relation to other people based on what access points your computer can see nearby. (I’m guessing this is not exactly precision–it’s probably accurate to a block or two.) They’re partnering with AOL to deliver location-based products, initially to instant messaging.
And here’s the company (Skyhook):