"The cell phone for some people is really an extension of who you are," said Scott Campbell, a University of Michigan assistant professor who studies how cell phones affect society. "It represents you symbolically. The way it looks, the way it sounds — it represents what your interests are."

Perhaps that's where the real conflict lies — when the mobility and individuality made possible by cell phones comes into conflict with the conformity and close proximity found in many workplaces.

"Cell phones really give a lot of people the freedom and autonomy to do what they want to do, and that does irk authority figures," said Campbell. "It creates an underlying tension."

It also creates a workplace cacaphony of incoming calls.

"Folks will pick different ring tones for different people," said Campbell, which means you could be hearing James Blunt for a lover, hip-hop for a friend, Sinatra for Uncle Frank.

That's OK when walking down a city street, perhaps, but it can create audible chaos for those within earshot in the nearest cubicle.

That's prompted human resources experts to take a look at what they can do. Nearly 40 percent of American companies had devised a written policy for cell phone use, and 10 percent more were working on one, according to a 2005 survey by the Washingon, D.C.-based Society for Human Resource Management.

Still, ring tones are tricky to regulate at work, said Chris Churchill, a Los-Angeles based human resources expert who helps companies devise policies for emerging technologies.

"What you might find loud, or you might find annoying, is a subjective thing," he said. "It's kind of like taste in music."

Churchill often recommends that his clients come up with blanket policies — i.e., all cell phones should be on vibrate or mute settings at work, or are outright banned in the office.