“This is a real geek fest,” says Professor Schalk, a high-energy physicist in both senses of the phrase.

“If I was a kid, I’d wet my pants here,” he joked.

Some 65,000 people came to see the sprawling display of inventiveness and potentially hazardous fun. Many of them read Make magazine and its sister publication, Craft, and go to Web sites like Instructables.com that encourage people to take on projects and share what they learn. (Recent online projects have shown people how to convert a novelty French-fry telephone into a carrying case for an iPod; how to make a computer-powered coffee warmer from an old Intel Pentium chip plugged into a P.C.’s U.S.B. port; and how parents and children can build a small vibrating robot together.)

Armchair MacGyvers visit Web sites like BoingBoing.net that lovingly chronicle the more audacious projects here and at events like the anarchic Burning Man festival in the Nevada desert. These overlapping, even incestuous, communities form the “maker movement” of do-it-yourself enlightenment. In an age where just about every human activity, from shopping to sex, can be performed in the virtual world, they choose to get their hands dirty.

This is part of the Bay Area’s high-tech, adamantly nonconformist culture, steeped in engineering and art and innovation in garages that incubate billionaires and crowded with guys who make late-night runs to the pharmacy for bandages and burn cream. But it is not just a California thing. Make has fans around the world, with a paid circulation of 100,000; its Web site gets 2.5 million visitors each month. The publisher has started a second Faire in Austin, Tex., with hopes of further expansion.

The founders of the magazine and the Faire are tugging on a thread that makes its way across America’s gearhead culture, zigzagging back through the Homebrew Computer Club, which helped produce the first personal computers, and Roy Doty’s how-to cartoons in Popular Mechanics magazine. But it goes farther still, back to those two bicycle mechanics, Orville and Wilbur Wright, and even back to those tinkerers Benjamin Franklin and Thomas Jefferson, whose hand-designed folding chairs are an elegant marvel.

What the makers are doing, then  mixing and matching technologies and hacking and tinkering  is encoded within the nation’s DNA.

Image Adam Savage of the TV show "Mythbusters" watched a demonstration. Credit... Peter DaSilva for The New York Times

“It’s deeply American,” said Xeni Jardin, an editor of BoingBoing. As for the family-friendly setting, she said, “It’s like Burning Man without all the icky hippie elements, without the pants-free guy on a bike.”