"X-Ray Specs! See Thru Clothing!" blares the copy, which is illustrated with a cartoon of a drooling geek wearing the amazing toy goggles and leering at a shapely woman.

Now, any kid with half a brain knew that X-Ray Specs were a novelty gag that didn't really work. But time marches on and technology makes the impossible possible. Stand by, air travelers, because the Homeland Security Department is preparing to install and test high-tech machines at airport checkpoints that will, as the comic-book ads promised, "See Thru Clothing!"

Get ready for electronic portals known as backscatters, expected to be tested at a handful of airports this year, that use X-ray imaging technology to allow a screener to scan a body. And yes, the body image is detailed. Let's not be coy here, ladies and gentlemen:

"Well, you'll see basically everything," said Bill Scannell, a privacy advocate and technology consultant. "It shows nipples. It shows the clear outline of genitals."

The Homeland Security Department's justification for the electronic strip searches has a certain logic. In field test after field test, it found that federal airport screeners using metal-detecting magnetometers did a miserable job identifying weapons concealed in carry-on bags or on the bodies of undercover agents.

In a clumsy response late last year, the department instituted intrusive pat-downs at checkpoints after two planes in Russia blew up from nonmetallic explosives that had apparently been smuggled into the aircraft by female Chechen terrorists. But it reduced the pat-downs after passengers erupted in outrage at the groping last December.

"The use of these more thorough examination procedures has been protested by passengers and interest groups, and have already been refined" by the Transportation Security Administration, Richard Skinner, the acting inspector general of the Homeland Security Department, told a Senate committee in January. Skinner said then that the TSA was ramping up tests of new technologies like backscatter imaging.

Last month, Michael Chertoff, the Homeland Security secretary, told a Senate subcommittee that "technology is really what we ultimately have to use in order to get to the next level" in security.

The technology is available, he said. "It's a question of the decision to deploy it and to try to balance that with legitimate privacy concerns," he added. "We haven't put it out yet because people are still hand-wringing about it."

Steve Elson isn't exactly hand-wringing. Let's just say he is mighty skeptical. A former Federal Aviation Administration investigator, Elson led the agency's red team of undercover agents who poked around airports looking for--and finding--holes in security.

"Backscatting has been around for years," he said. "They started talking about this stuff back during the protests when they were grabbing women. Under the right circumstances, the technology has some efficacy and can work. That is, provided we're willing to pay the price in a further loss of personal privacy."

He isn't. "I have a beautiful 29-year-old daughter and a beautiful wife, and I don't want some screeners to be looking at them through their clothes, plain and simple," he said.

Like many security experts, Elson argues for a sensible balance between risk management and risk reduction. On numerous occasions since the 2001 terrorist attacks, he has led reporters on test runs at airports, showing how easy it is to penetrate security throughout the airport.

Thwarting body-scanning technology would be simple, he argues. Because of concerns about radiation, body scanners are designed not to penetrate the skin. All that's needed is someone heavily overweight to go through the system, he said. I won't quote him directly on the details; suffice it to say he posits that a weapon or explosives pack could be tucked into flabby body folds that won't be penetrated by the scanner.

Homeland Security has not identified the airports that will test backscatters. More than a dozen have been selected to test various new technologies.

One maker of backscatters is Rapiscan Security Products, a unit of OSI Systems. "Since the Russian plane tragedy, which is suspected due to suicide bombers, the interest has heightened for these needs, especially for the body scanner," Deepak Chopra, the chief executive of OSI Systems, recently told analysts.

Scannell, the privacy advocate, scorns that reasoning as alarmist nonsense. He does see one virtue, though, for some airport screeners if backscatting technology becomes the norm.