Track people via their cell-phones
Not just for the Government anymore! Now track your "friends" via Google, who deduces where they are via the GPS chip in your cell phone, which tower your phone is communicating with or which WiFi hotsport they're talking with.
Google is using technology that's similar to that of Skyhook Wireless in its Latitude service. Like Skyhook, it is a software-only location solution that allows any mobile device with Wi-Fi, GPS or a cellular radio to determine its position with an accuracy of 10 to 20 meters.
(From computerworld)
Also according to this CBC article it will be illegal to sell a cell phone in Canada which CAN'T do this starting next year (Feb 1, 2010).