In World War II, a little-known product called "duck tape" kept cases of ammunition dry. Soldiers also found it useful for holding together parts in jeeps, guns and even aircraft, and the tape went on to commercial fame as "duct tape," used for sealing duct seams and countless other household tasks.

In the 1991 Gulf War, widespread use of Global Positioning System devices put that satellite technology on the map and helped make GPS a household name. Devices using GPS to get a fix on location became commonplace in cars and in handheld units used by hikers and other outdoor enthusiasts.

Recent conflicts have likewise elevated the military's high-mobility multipurpose wheeled vehicle -- the HMMWV, or "Humvee" -- to a consumer status symbol under the Hummer brand name, for those who can afford the $50,000 price tag.

Now, the battlefield has again become a harsh and sometimes deadly laboratory, a proving ground for technologies that are serving one purpose today but will probably serve civilians in different ways tomorrow.

Technology experts and military historians watching the unfolding war in Iraq note that with the digital age well underway, much of the weaponry on display builds on systems used in the first Gulf War and leverages dramatic civilian advances in technology.

But they are intrigued by the expanded use of technologies such as drones, small unmanned aircraft that can crisscross large swaths of territory and provide intelligence data.

Whereas the 1991 war's technology was defined by the ability to pinpoint location, experts say this war will be known for extending the ability to remotely see, hear and gather information.

"We're seeing fuller exploitation of persistent surveillance," said Owen Cote, a defense technology expert with the Security Studies Program at the Massachusetts Institute of Technology. "We're infesting the battlefield with UAVs," or unmanned aerial vehicles.

Unmanned Predator drones are used as attack vehicles, carrying missiles that were used to kill suspected al Qaeda officials in Yemen late last year.

But for surveillance, camera-carrying UAVs can come in packages as small as six inches across and weigh about two ounces.

One such vehicle, called the Dragon Eye, is built to be taken to the battlefield in a backpack. A bungee cord serves as a kind of slingshot to launch the vehicle before its electric motor takes over. The operator directs it with a laptop computer.

A spokesman for AeroVironment Inc., a Monrovia, Calif., maker of UAVs for military and law enforcement use, said the vehicles his company makes are not available for civilian use.

Among other things, he said, they would need to conform to Federal Aviation Administration requirements, and the remote-control devices would need to use frequencies licensed by the Federal Communications Commission.

But Paul Saffo, a director of the Silicon Valley-based Institute for the Future, expects to see UAVs in wide civilian use within five years.

"Teenage nerd hobbyists will be able to buy or build UAVs that will be a little larger than a paperback book," said Saffo, whose work includes predicting how consumers might incorporate new technologies in their daily lives. "Nobody will be able to comfortably sunbathe topless in their backyards anymore."

Daryl Davidson, executive director of the Virginia-based Association for Unmanned Vehicle Systems International, said that small drones carrying still cameras are beginning to appear in advertisements in airline magazines.

"It probably won't become like the kite festival down on the Mall," Davidson said. "But the commercial opportunities are limitless."

Saffo said the devices are likely to gain wider usage for law enforcement, fighting forest fires and monitoring traffic.

"The revolution is about hanging eyes, ears and sensory networks onto other networks," he said.

Aiding the cause, said Cote, is military leadership in the use of radar and sensor technology.

"Sensors are going to be very big," said Cote, who defines a sensor as anything that creates a signal, sends it out and then collects return data.

Enhanced radar -- which can better penetrate foliage, buildings and the ground -- is helping the military find possible targets and detect dangers.

Cote envisions numerous civilian uses for improved sensors, such as in automobiles to warn a driver when another car is too close, or to improve ultrasound and other medical devices.

Chung-Chiun Liu, a professor of sensor technology and chemical engineering at Case Western Reserve University, said new sensors can provide health monitoring on patients' wrists, with data streamed continuously to a doctor or hospital.

Alex Roland, a professor of military and technology history at Duke University, speculates that advances in unmanned vehicles and sensor technology will combine to change future warfare overall, making it an even more remote-controlled endeavor than it already has become.

"More and more [combatants] will disappear from harm's way, and machines will be doing more," Roland said.

Not all new technologies are being used to inflict damage to the opposition in Iraq.

The Navy is using the first full-scale, "deployable" hospital, a mobile medical center complete with wireless networks, voice-over-Internet telephony, and electronic links to computer servers that house medical data and patient records.

"One of the features is that it's all electronic," said John Spotila, president of Chantilly-based GTSI Corp., a systems integrator that contracts with government agencies. "There are no paper forms or files."

Spotila said such systems could be used by disaster-zone emergency teams, such as the Federal Emergency Management Agency or the Red Cross.

Among the integral elements of the deployed hospital are "ruggedized" laptops and peripheral equipment, which are built to absorb shocks and withstand dirt, dust and water. These were already growing in popularity with truckers, marine operators, aviators and emergency-response organizations, as well as with the military.

But whether the bulkier, heavier and more expensive laptops will become a consumer favorite is an open question.

Not everything has the widespread appeal and staying power of duct tape.

U.S. Air Force personnel work on a Predator unmanned aerial reconnaissance plane at an airbase in an undisclosed location near Iraq. Technologists predict that unmanned craft will be more widely used for non-military purposes.