To be sure, that coping strategy raises its own challenges. For one thing, the desire to find time with fewer interruptions is a constant theme among the people whom the anthropologists have studied. For another, the place where knowledge workers find the most uninterrupted time is most often at home -- which raises a whole new set of challenges. "When I look for the boundary between work and family, I can't find one," says English-Lueck.

That's true in both directions. Home life permeates the workday, with frequent phone calls and emails zipping among husbands, wives, and kids, confirming and modifying the family's "daily strike plan." On the flip side, discussion of work pervades the home. Couples often go beyond using each other and their kids as sounding boards, drawing on their talents for help. "It's as if there's an unpaid consultant in the other spouse," explains English-Lueck. "Often, companies aren't just hiring one person; they're hiring an entire family -- all of the skills and knowledge of that pool."

What's more, it's not just the demands of work that are infiltrating our personal lives; the language and mentality of work also affect life at home. "If you listen to families talk today," says Darrah, "the concept of management -- backpack management, time management for homework -- is ubiquitous."

Silicon Valley residents are constantly attempting to create a boundary between work and life: "No working at the dinner table" and "No working in bed" are common household rules -- rules that are frequently broken. Some people, though rare, deliberately don't have a computer at home. Others create a geographic boundary by living in a remote location, such as the Santa Cruz mountains, so that a lengthy commute becomes a border. Explains English-Lueck: "The thinking is 'If I have to spend 90 minutes commuting, then by the time I get home, I'll really be home.' Of course, that's not exactly true."

What she means is that work persists in entering the home. "You might not bring a briefcase full of work home, but you're still thinking about work," says English-Lueck. "The work is in your head, and that's much harder to manage."

It's the knowledge worker's ultimate work-life dilemma: If work is just as much about thinking as it is about doing, then how can you ever truly get away from it?

Katharine Mieszkowski (km@salon.com), formerly a senior writer at Fast Company, now holds that title at Salon.com. Contact J. Neil Weintraut (neil@21vc.com) by email, or visit 21st Century Internet Venture Partners on the Web (www.21vc.com). Contact Jeff Levy (jeffl@ehatchery. com) by email, or visit eHatchery on the Web (www.ehatchery.com). Contact Jan English-Lueck (jenglish@email.sjsu.edu) and Chuck Darrah (darrahc@email.sjsu.edu) by email, or visit the Silicon Valley Cultures Project on the Web (www.sjsu.edu/depts/anthropology/svcp).

Sidebar: Dual Career or Duel Career?

"The daily strike plan." That's the term that a team of anthropologists uses to describe the logistical schemes that guide Silicon Valley moms, dads, and kids so that they can all get where they need to be -- work, day care, school, after-school activities, doctors' appointments, friends' houses -- when they need to be there. What's notable about these plans, whether carefully or carelessly wrought, is that they almost always change at some point throughout the course of a day. Life has become a daily dance of negotiating and renegotiating household activities -- while family members are at work or at school. One subject emailed Jan English-Lueck, one of the San Jose State anthropologists, quipping: "I don't think it should be d-u-a-l career -- it should be d-u-e-l career."

In their studies of two-career couples, the researchers have observed a frequent, even on-the-spot, shifting of priorities between spouses, depending on who has the greatest flexibility. Explains English-Lueck: "Who pays attention to work? Who pays attention to kids? It isn't as simple as one person having the kid role and the other person having the work role. You're constantly shuffling back and forth, as the demands of each role change."

During his research, anthropologist Chuck Darrah watched as a Silicon Valley worker made and received 26 phone calls in the course of a single day, 18 of which were personal. But this wasn't a goof-off employee, slacking away the day gabbing to friends and family on the phone. Almost every call was less about chatting than about arranging and orchestrating the logistics of family and home life.

Coworkers often act as a kind of personal safety net to remind one another of their familial obligations: "Don't forget that you have to take Samantha to the dentist at 4 PM today." A frequently expressed concern among parents is the fear of losing track of a child for a few hours, by perhaps forgetting to pick that child up from day care.

Sidebar: The Business of Speed