Now she is looking to move on. Like a growing number of industry veterans, Harmel has begun searching for a house away from the nation's technology hotbeds -- South Carolina is her choice -- and is planning to eventually sell her business and leave the industry. "We're burned out," Harmel said, speaking of Net entrepreneurs of a certain level of experience and fatigue. "Some of us are tired and rich. Some of us are tired and not rich. But we're all tired."

Data on this topic are scarce, but anecdotal evidence suggests that a changing of the guard is under way in the Internet industry, as the early proponents of the Web are stepping aside for the mainstream business people who have migrated to the new medium. Such a cultural shift was to be expected, given how the Web itself has become a mainstream phenomenon. But analysts say the executive shift could have broad implications for e-commerce.

"Call this Web 2.0," said Clay Shirky, a partner at Accelerator Group, a consulting firm that works with Web start-ups, who has worked in the Internet industry since 1993. "This has been going on slowly, and now people are realizing the landscape has changed without us having caught onto it."

The changing culture within Internet businesses -- from a work force of "young, revolutionary zealots" to one with a more mainstream corporate ethic -- "is a necessary thing," Shirky said. "For the Net to be genuinely revolutionary, it has to be genuinely ordinary," he said. "So it has to be normal within the business world, too."

But losing the revolutionary zeal and the wisdom of the Web's early leaders could also change the pace of innovation, Harmel and others said, as the more managerial types replace the tinkering pioneers. But then, in many cases, there may not be many insanely great ideas left in the brains of the old guard, either.

"It's tough to contribute good, new ideas and keep stuff going if everybody's sitting at home eating Fritos, comatose from four years of working this hard," Harmel said. "Lately, when you ask people how it's going, you constantly hear them say, 'I'm tired. I want my life back,"' Harmel continued. "For me, it's time to focus on what's important in life: family, food, sleep."

Internet veterans who are considering a hiatus or a new career say the hours have been brutal. But they also say the relentlessness of their jobs was easier to accept when the focus was on exploring the creative possibilities of technology, not constructing a blueprint for a public company.

"The clash of the cultures is there," said Mark Hurst, president of Creative Good, a Web site consulting company in New York. Hurst, who is 27 and started working on the Internet immediately upon leaving MIT with a master's degree in computer science in 1995, said he was planning a sabbatical to write a book about what he called "bit literacy," which would explore how people can avoid being overwhelmed by Internet technology.

"Three years ago, things were still fresh, a little more hopeful, less cynical than they are now," Hurst said. "People who were part of that original culture see what the game is about now, and they're saying, 'This isn't what I came here for. If you want it so bad, you can have it. I'm going to go scuba diving."'

Or sailing, in the case of Catrina Gregory, who recently quit her job as vice president for business development at UPOC.com, which provides services to wireless Net users. After two years of working "insane hours" for Web companies, Gregory, 29, is taking several months off to learn sailing, get her pilot's license and plan her next career move.

Gregory's first dot-com employer, Sabela Media, was purchased by another Web advertising firm, 24/7 Media , in January. "So I went from this small start-up environment to being part of a behemoth," she said. "It was tough for me to get up and say, 'I'm going to make 24/7 stronger, faster, better."'

Saying that Sabela's sale to 24/7 Media did not make her rich, Gregory added: "For those of us who haven't ended up gazillionaires, the question is, 'How much longer am I willing to put off personal happiness?' So many people have stock options that are worthless, and without that bait, why stay with something you don't really like doing?"

The chances of her returning to a dot-com after the hiatus, she said, are "less than 50 percent."

Scott Heiferman, who founded i-Traffic, an online marketing company, in 1995, and sold it to Agency.com in November, said there was "definitely a bit of burnout in this industry." Heiferman, 28, who earlier this year founded RocketBoard, a company that makes keyboards designed for Internet use, added that he was "concerned about the implications of this, because an intensity and strong sense of purpose can make miracles happen."

"But in another sense, this is textbook stuff," he said. "The bigger any company gets, the tougher it is for dissenting voices to come through or for innovation to happen. I think there will still be passionate people in the industry. Maybe there will just be fewer of them on a percentage basis."

Heiferman said he agreed that working conditions had been difficult for dot-com employees over the last several years. "But for better or worse, there was a revolution going on, so it was no time for people to pace themselves," he said. "It was a time to go full steam."

Shirky, of Accelerator Group, said some executives still wanted to go full steam, but because of the changing nature of e-commerce, they wanted to do it in a different industry. "I've had a number of conversations with people who've said, 'Oh, maybe I'll go into biotech,' as if that industry needs the same energy and input as they put into the Internet," Shirky said.

"They figure that if the Internet isn't where the revolution and action is anymore, then the action must have just gone somewhere else," he added. "What they don't realize is that it's just gone, period. The Internet is a once in a lifetime thing."