What's turning women away?
The wireless industry turned to foreign women when it couldn't fill its ranks in the United States, taking advantage of the controversial H-1B visa program. "A lot of people were available through the H-1B from Europe and some from Asia, where there hasn't big an issue of getting women into engineering and computer science programs," Casey said. "In the U.S., it continues to be an issue."

In fact, the issue has gotten worse. In 1985, 37 percent of computer science undergraduate degree recipients were women. In 2006, just 21 percent were.

Simson said she suspects the decrease in women's enrollment in high tech is due to the stigma associated with long hours in a very demanding field with lots of economic up and down cycles. "It is associated in the minds of people as not stable," she said.

The combination of instability and demanding hours also gives women an unpalatable choice between work and family, she noted. Men can more easily make the choice to work because women still typically manage the family, even if they have careers. Women get to a certain level, then have to decide whether to pull back a bit or change their career track because of the needs of the family — or to put their husbands' careers first, Major said. "The culture hasn't changed," Simson said.

The balance issue is more acute if your goal is to be in the top executive ranks. "The price you pay as a CEO or top executive is very high, whether you are a man or a woman. It takes up a lot of personal time, a lot of effort, a lot of travel. You are watched all the time. People do not realize how much they have to give up for one of those top spots," Major said. "Companies are demanding, and they want you to put in 60-hour weeks."

At that level of demand, the choice between career and family is almost inevitable, Major said. No matter how supportive a husband might be as a partner, it's tough to find the balance, to have a family and keep up as a CEO in a man's world, she said.

Another factor that keeps women out of the tech field is that the industry's image is not compelling. "The image of computing is still a white geeky guy sitting by a terminal eating junk food," Simson said. That stereotype is misplaced, even if there are ready examples at most workplaces. "Women need to understand that full range of computing, that it requires critical thinking and problem solving in addition to programming," Simson argued.

And then there's the elephant in the room, Major said: "It's still a man's world."

Still, with all the issues that may discourage women from entering technology careers, an important fact is often lost. "It is a wonderful career," Casey said. "Computing is a powerful partner and fundamental to everything in the world today."