Three years ago, on yet another fund-raising walkathon through the streets of San Francisco, Supervisor Nancy Walker started adding things up. Here was a city in which the majority of the supervisors were women, the mayor was a woman, and the two members of Congress were women. But the sum total of their efforts didn't impress her.

"I couldn't look at one thing we'd done to keep a commitment to the women's community," said Walker. She walked and thought about the lack of a women's agenda, and the need for women to hold their elected officials accountable. "Our interests always get put on the back burner. We say, "Oh well, we'll wait until next year.'

Walker decided to hold herself accountable. When the local Child Care Law Center drafted an innovative day- care ordinance, she got hold of it and said, "Let's just do it." And they did it.

Today, San Francisco is the first U.S. city with a law that makes developers of major new projects provide rent-free space or ante up $1 a square foot for nearby child-care centers. No child care, no building approval.

"I expected them to scream like stuck pigs," says Walker. But opposition has been muted. At least one major developer is reportedly ready and waiting for the regulations to be completed so he can come aboard. Maybe San Francisco developers are getting conditioned to public-minded strings on private projects.

After all, the new zoning laws also mandate a budget for art. As Walker says, "If you hang a piece of art for $8,000 in the lobby, why not put kids in the building? They change every day, and people never get bored with them."

Aside from the aesthetic beauty of preschool mobiles, on-site day care may also make some business sense. It gives the developer a competitive edge in selling space to corporations, especially when the city has an office vacancy rate of 12 percent. It gives the corporation an edge in hiring and holding the loyalty of a young work force. It is no secret that a worker's performance goes up when anxiety about the children goes down.

But the real profit motive behind this ordinance is for the working families of the Bay Area. As with families in every city in the only industrialized nation in the world without a day-care policy, there are more children here in need of day care than there are places to care for them.

To boil all the stories down to statistics, half the mothers of preschool children in the Bay Area are working; one child in five lives in a single-parent family, and last year there were 10,000 requests to the city's child-care coordinator that went unfilled. About two- thirds of those who need child care can't afford the average $450 a month. Nevertheless, it's taken a long time for day care to become a breaking issue.

Traditionally, most corporations have enlisted parents in their work force without assuming any responsibility for child care. The amount of energy needed to lift child care off the corporate launching pad has been intimidating. Families that need child care most often have the least leftover fuel to expend in organizing.

The major attraction of the new San Francisco law is that it will not only enlarge the number of child-care slots and lower the costs, but will also bring care closer to the parents' work place. This is more than a convenience; it gives parents a stronger connection to centers and a chance to lunch with and visit their preschoolers.

The San Francisco ordinance is only a modest first step in forging a private/public partnership for kids. But it's a decent example of what can happen when women use power to get a piece of that agenda "off the back burner."

There are sill some who find the notion of putting child care in downtown skyscrapers a bit peculiar. When outsiders talk to Walker about the plan, "They say to me, 'Can you imagine gray-suited executives riding up the elevator to the 26th floor with a bunch of sticky-fingered kids?' I say, 'Yeah, I can. It would do them a world of good.'

Well, here comes that world of good. The sticky-fingered kids are on their way to the San Francisco work place.