Boing-Boing covers a news story about a guy in L.A. who was stalking his girlfriend with the aid of a Nextel GPS device. Not sure which device actually fits this description:

"Gabrielyan had purchased a Nextel phone device that has a motion switch on it that turns itself on when it moves. As long as the device is on, it transmits a signal every minute to the GPS satellite, which in turn sends the location information to a computer."

I wouldn't mind finding out more about it, as I can think of legal ways to leverage that as a data-gathering device (GPS or not).

My first reaction, truly, is a slow, dissapointed sigh -- not in the nature of this man's inability to deal with his own shit instead of terrorizing someone else with the aid of modern technology -- but in that the takeaway from this, for the press and in the general public, is that GPS for consumer applications is inherently dangerous, ridden with privacy issues, and only useful for nasty-ass big brother applications. I've built a few tracking/GPS cellphone apps, and I've scaled back planning and prototyping way back to avoid the inevitable sense that it has some evil use at it's core. While I certainly feel that perception needn't be that way, I'm not naive enough to think that advanced tracking and location wouldn't be used for breaking the law.

I'd love to build a killer app for GPS on the phone. Just not literally.