Google, Yahoo and Microsoft desperately want to know every last thing about what you do, say and buy. Here's how they'll do

By David H. Freedman
Newsweek International
April 3, 2006 issue - A friend takes your picture with her cell phone, and puts the phone back in her purse. But the gadget isn't dormant. It gets to work figuring out who you are, and sends that information, along with your precise location, to an organization that adds the data to a file it keeps on where you go and who you hang out with, as well as other things. The organization then charges money to help others who want to reach you, and even notifies certain people nearby of your presence.