The first lock is the hardest,but once the locator has your position it will keep up with you in five-minute blinks.

The possibility of tracking workers on jobsites by remote sensing got a leg up in October with the release of a new homing device. Through a web browser used by an authorized employee, it can report a worker's location.

The PocketFinder Personal GPS Locator is like a GPS-enabled cell phone—without the phone. The device uses global positioning satellites to find its location and a GSM-based cell-phone network to call that location in every five minutes. If satellites are blocked by foliage or other obstructions, the device can triangulate its location with cell towers. It will capture up to about 2,400 waypoints and can display by the hour or the day. History reports of days, weeks or months can be generated as PDFs.

“We selected GSM AT&T because it's worldwide, almost 97% of the wireless world,” says Dave Michael Morse, vice president in charge of customer service.

The firm has a relationship with Apple, and the devices can be tracked on iPhones, iPads and the iPod Touch with a free app from the iTunes App Store. The devices also can be tracked on any web-enabled phone by logging in to a user's account through a browser. Sales are handled by Apple.

The $149 devices cost $12.95 a month for the service, although Morse says the company will be willing to discuss rates for large groups of users after the device has been on the market a bit longer. “We've just launched, and until we have six to eight months of real data, we are working off of a model, but I could see business plans or family plans,” he says.

A vehicle version is also available. Morse says one of the first commercial users was a London bank, which used the device to track an executive traveling to Zimbabwe to close a deal. “They wanted to know where he was, and they got a device to send with him.”