Hampton fourth-graders are among the latest players in a high-tech treasure hunt that can involve participants from around the world.

Equipped with hand-held Global Positioning Systems, pupils at Poff Elementary School marched into the woods behind their school last week to play a new adventure game called Geocaching.

Seventy kids split into three groups to search for places to hide their "caches" -- plastic containers filled with trinkets, a log book, game rules and what is called a Travel Bug, a traceable tag that is moved from cache to cache, with its whereabouts recorded online.

"This is more fun than a scavenger hunt!" said Jessica Argenas, 10, as she watched her classmates place a cache along a wooded trail.

"Geocaching is a great hobby to incorporate teaching in different academic disciplines, including math, science, technology, geography and phys ed," Poff Principal Michael Mooney said.

Global positioning systems track a holder's position by reading signals from at least four of 12 satellites circling the Earth. When the latitude and longitude coordinates of a cache are entered into the system, it can tell where a cache is hidden with an accuracy of up to 50 feet.

Finders of a cache do not move it from its hiding place but are expected to record their visit in the log book. They may take one or two items out of the cache, and they're supposed to add something of their own. Travel Bugs are meant to be removed and placed in a new cache, preferably far from the cache in which it was found.

More than a dozen Geocaches are in North Park, and at least half that many are in the forests of Hartwood Acres, according to Mooney. Hampton Community Park has three, and new caches are being placed around the world all the time.

At the center of the new sport is the Geocaching Web site, www.geocaching.com. Players establish free accounts on the Web site using nicknames they've created for themselves, and they can find the location of caches all over the world -- or in their own neighborhoods.

Already part of Hampton Middle School's curriculum, Geocaching was introduced to the Poff pupils in May by Glenn Geary, technology education teacher at the middle school.

"It took a while for the kids to understand what they were reading [on the devices], but they couldn't wait to get started," Mooney said. "It's amazing. You can actually track yourself as you're walking. It's like playing a hide-and-seek game with an electronic toy."

The hand-held positioning devices used by the Hampton pupils are about the size of a cell phone and usually cost a little more than $100 each, but the district got them for $85 each.

Mooney successfully applied for a $900 grant for the program from the Hampton Alliance for Educational Excellence last summer.

"The [alliance] is a nonprofit organization that raises funds from the business community for programs aligned with the district but not funded by the district," he said.

The school received additional funding from Wal-Mart.

The district hopes that Geocaching will be a family activity for pupils.

Mooney has sent home information to parents to explain the game and to help them find caches placed in the Pittsburgh area or throughout the world.

"Summer vacations will never be the same," he said, laughing.

"We'll put a CD in the library about Geocaching, which explains everything -- from the basics to the higher-end aspects," Mooney said. "We want this to be a family hobby, so we also have a sign-out form for families to do this over the summer."

The fourth-graders chose themes for their three caches -- sports, school supplies and key chains -- and noted on the Web site that their caches are intended to be found by families.

The district plans to introduce Geocaching in fourth grade and carry the lessons on through middle school.

Fourth-grade science teacher Shanan Wilson said her pupils are excited about finding the caches hidden by the other pupils. "They're loving this," she said. "We've spent the last few weeks collecting items to put in the caches and creating user accounts on the Web site."

But what they loved most was traipsing through the woods on a high-tech mission from space.

"Using satellites is fun," said Zachary Gonzales, 10. "It's neat that there's something in space helping you find things on Earth."