Stephen Petilli doesn’t worry about getting lost, even when he’s driving in unfamiliar territory.

He’s chief executive officer of Networks in Motion, a start-up company in Irvine, Calif., that has turned cell-phone handsets into personal navigators. He carries a prototype mobile phone that literally tells you where you are and how to get where you’re going.

When he flew to San Jose, Calif., for a recent meeting in Palo Alto, Calif., he didn’t bother to get directions in advance.

He simply rented a car, entered his destination into his cell phone, and glanced at the full-color map and directions on its screen. He wanted to keep his eyes on the road, so he turned on the phone’s speaker, which read him turn-by-turn directions.

So far, these souped-up phones aren’t available, but NIM (another name for the company) is already selling less powerful versions of its service.

Its most advanced product, AtlasTrack, works with Global Positioning System satellites and Nextel’s wireless network, allowing businesses to monitor employees’ whereabouts. It’s designed to track messengers, cable TV installers, construction workers, sales personnel, and other workers who are constantly out in the field.

Radio chips in the phones send messages to the home office as often as once a minute, allowing a dispatcher to:

-Identify the location of the phone, and whether it’s stationary or moving.

-Pull up maps that show the current location of all employees.

-Click on the name of a particular worker to get a map of the route traveled that day, along with specific addresses visited, and even the vehicle’s speed at any particular moment.

-Get an automatic warning whenever a driver is stuck in traffic or speeding.

Employee-tracking cell phones are an expansion of electronic monitoring conducted by many companies. Techniques include audio and video surveillance, as well as routine screening of e-mail and Web use.

The Privacy Rights Clearinghouse, a consumer advocacy group in San Diego, generally opposes use of such technologies, except in cases where employers have good reason to suspect an employee of wrongdoing.

But the use of GPS is a reasonable way for companies to manage mobile work forces, according to Beth Givens, the group’s director.

“There are good business reasons for using it. But it must be coupled with a very robust privacy policy,” she said.

Companies should clearly communicate those policies to all employees, and never use GPS data as the sole basis for documenting negative reports on a worker, she said.

For example, if a GPS system were to alert a dispatcher that a truck driver was regularly speeding, a supervisor should discuss the matter with that employee so that there’s an opportunity for the worker to dispute the data.

The NIM dispatch system monitors drivers, but doesn’t give them directions.

NIM plans to introduce its wireless navigation systems later this year.

It’s one of several companies developing products that use GPS to help with navigation.

In March, a prototype of its AtlasBook Mobile navigation system won a gold medal in a contest that’s essentially the Olympics of GPS devices.

After testing products from a group of semifinalists on the streets of Atlanta, judges awarded NIM the grand prize.

That title could give NIM a leg up as it competes for business with rivals such as Road of Fremont, Calif., which has long been selling less sophisticated and bulkier tracking systems known as black boxes. It offers a fleet management service that also works on Nextel phones.

NIM is also going up against wireless industry heavyweight Motorola Corp., which last year introduced a turn-by-turn cellular navigation system dubbed Viamoto.

In April NIM introduced AtlasBook Places, a $4.25-a-month service for consumers that works on the Verizon Wireless network. Unlike Viamoto, the NIM product doesn’t work with GPS satellites.

Instead, it provides maps and driving directions that come from a Web browser, plus yellow pages searches. Verizon Wireless isn’t heavily promoting the product.

NIM’s business product, AtlasTrack, has been on the market for about a year and has a small but loyal following.