Privacy advocates say the lack of legal clarity about who can gain access to location information poses a serious risk. And some users say the technology threatens an everyday autonomy that largely is taken for granted. The devices, they say, promote the scrutiny of small decisions — where to have lunch, when to take a break, how fast to drive — rather than a more general accountability.
"It's like a weird thought I get sometimes, like 'He definitely knows where I am right now, and he's looking to see if I'm somewhere he might not approve of,' " Britney said. "I wonder what it will be like when I start to drive."
Still, personal-location devices are beginning to catch on, largely because cellular phones, the most popular device of the communications age, are increasingly coming with a built-in tether.
A federal mandate that wireless carriers be able to locate callers who dial 911 automatically by late 2005 means that millions of phones already keep track of their owners' whereabouts. Analysts predict as many as 42 million Americans will be using some form of "location-aware" technology in 2005.