Great article from Technology Review called “WhereWare”:

“The idea is to make cell phones, personal digital assistants, and even fashion accessories capable of tracking their owners’ every movement — whether they’re outdoors, working on the 60th floor, or shopping in a basement arcade.”

Most of what I’ve seen on this topic has focussed on location-based advertising (as in “The Gap can beam discount coupons to you as you pass their store!”). Most of this is uninspired hogwash that serves companies well, but not people. Some of the examples in this article speak more to personal use (finding out if a loved one is on their way to meet you or hopelessly lost, walking directions, etc.).