Want to know where your kids are 24/7? The distance you biked last week? How about the yardage of your next golf shot from fairway to hole?

Global Positioning System satellites make it easy. Consumer devices using GPS technology to measure distances and pinpoint locations are turning up everywhere these days.

Ever since the U.S. military fully opened the system to the private sector in 2000, the market for GPS devices has boomed, said Steve Koenig, senior manager of industry analysis for the Consumer Electronics Association, an industry trade group.

Nearly one adult in five owns some kind of GPS-enabled device, and one in four plans to buy one within a year, according to a recent CEA survey.

Koenig attributes the growing demand to increased competition and advances in related technologies that are allowing GPS to be used in ways like never before. People today, he said, expect a GPS device to do more than just pinpoint a location.

Take, for example, Blue Heron Golf Club in Medina, which put in a top-of-the-line GPS system when it opened two years ago.

Screens in each of the club's 120 golf carts show golfers how far they are from the hole. And during tournaments, players can see how they're doing compared with their competitors, said David Knox, director of golf operations at the club.

"It's a very big selling point for us," said David Martin, an assistant golf professional at the club.

Knox said the system is also a helpful tool in managing the course, showing how long each group is taking to play.

Blue Heron's system was designed by Arizona-based ProLink Solutions, which has installations at more than 500 golf courses. It is one of several emerging companies that are creating GPS products for niche markets.

Another is GlobalPetFinder in New York, which has patented a tracking device that fits on a dog collar. If the dog leaves a defined area, the customer receives a text message or an e-mail with the street address closest to where the dog has wandered.

This product is for the true dog lover, though. The device alone fetches $289.99, and the service is another $17.99 per month. Still, "Sales are steadily increasing as the word is getting out," said office manager Tammy Smart.

The first common consumer use for GPS, personal navigation from one point to another, remains the most popular, said Koenig of the electronics association.

Most of the early devices were installed in automobiles. But now, handheld devices are outselling after-market fixed units 20 to one. People like the mobility, features and services that portable units offer, he said.

The leading manufacturer of GPS devices, Garmin Ltd., derived 60 percent of its $1.8 billion in revenues last year from sales of portable units, spokesman Ted Gartner said. Handheld devices also can provide information on traffic, weather and nearby businesses.

Garmin has partnered with Sprint and with Research In Motion, creator of the BlackBerry, to offer personal navigation software in mobile devices. In the recent CEA consumer survey, one-third of those who said that they're planning to buy a GPS device in the next year were interested in a cell phone with GPS features.

"You look at all the things available on your cell phone today: downloading music, reading e-mail, watching TV," said Laura Merritt, a spokeswoman for Verizon Wireless. "People are so mobile today that they want to be able to do whatever they need to do, no matter where they are."

Verizon and other wireless carriers offer an array of services using GPS, including tracking kids, giving directions and managing vehicle fleets.

Verizon family plan customers can opt for a service called Chaperone that allows parents to set geographical boundaries for their children. If a child takes a cell phone beyond that area, the parent is notified -- unless the child has turned off the phone.

Window and door distributor Gunton Corp. in Bedford Heights uses Verizon's fleet-tracking option to keep tabs on its 18 local field technicians and 11 delivery truck drivers, said Ed Weinfurtner, executive vice president.

The service helps Gunton come up with more efficient routes for its drivers. And when a customer calls for service, workers can look on a digital map to find the nearest technician.

"It addresses things we have not been able to address for years," Weinfurtner said.

Dennis Abrahams, chief executive of SageQuest in Beachwood, is hoping more companies will recognize how GPS can help manage fleets more efficiently. SageQuest designs and installs similar GPS-based fleet-tracking systems.

"Of all the companies that could use this, only 5 to 10 percent do," he said. He estimates that another 40 percent will put in GPS systems by 2012.

GPS is making inroads with fitness freaks, too.

Doug Charnock of Peninsula, a regular biker for 15 years, paid about $250 last year for a Garmin Edge 205. He used the gadget as a training tool that automatically recorded his distance, speed and riding time.

"A lot of serious riders have a diary where they write everything down," he said. "This does it all for you."

But Charnock's GPS unit was crushed -- and so was he -- when it fell to the pavement and was run over. Now he's trying to locate the money to replace it -- something not even GPS technology could help him with.