Flutterby™! : cell phone tracking

Two recent court decisions are split on legality of tracking you via your cell phone:

It's also unfortunate because it demonstrates that the FBI swore never to use a 1994 surveillance law to track cellular phones--but then, secretly, went ahead and did it, anyway.

This came via Jay), who mentions GPS, but it's important to note that this current situation isn't using GPS, it's just using signal strength and triangulation from the towers, and that their accuracy with that (I'm told by a guy who develops apps for it) is about half a block.