Tired of calling your friends to find out their every move? Save youself the trouble by subscribing to one of several new services that take advantage of built in GPS to let you track others on your phone.
Because it's their job, the Electronic Frontier Foundation is a little worried:
"There are massive changes going on in society, particularly among young people who feel comfortable sharing information in a digital society," said Kevin Bankston, a staff lawyer at the Electronic Frontier Foundation based in San Francisco.
"We seem to be getting into a period where people are closely watching each other," he said. "There are privacy risks we haven't begun to grapple with."
But, once again, lots of people's purchasing decisions seem to show that they're happy to swap privacy for convenience:
Kyna Fong, a 24-year-old Stanford graduate student, uses Loopt, offered by Sprint Nextel. For $2.99 a month, she can see the location of friends who also have the service, represented by dots on a map on her phone, with labels identifying their names. They can also see where she is.
One night last summer she noticed on Loopt that friends she was meeting for dinner were 40 miles away, and would be late. Instead of waiting, Fong arranged her schedule to arrive when they did. "People don't have to ask 'Where are you?'" she said.