Rachel Metz:
>Called Placeme, the free app takes advantage of the smart phone’s sensors and its GPS and Wi-Fi capabilities to figure out where I go and for how long, and stores this data in a private log on my iPhone.

>It may sound creepy or unnecessary, but as more people carry smart phones with them everywhere, demand for this kind of persistent location tracking may grow—not just from marketers, but also from individuals who want to keep an eye on their own movements or of loved ones with medical conditions such as Alzheimer’s.

Correction, it *is* creepy and unnecessary. More than just that, potentially very dangerous if you lose your phone.