This time around, however, the killer apps probably won't develop in quite the same way. We'll hear fewer tales of tiny businesses that start in garages and dorm rooms - like Hewlett Packard and Yahoo did - and then grow into household names. The Valley's new emerging businesses require government funding, deep expertise, and elaborate research facilities. "We're talking about electron microscopes and federal research labs," says Hancock. "It's not going to happen in a dorm room."

Creating an environment where this generation of start-up can flourish will require new skills: lobbying government and acting collectively, for instance. Traditionally, the Valley has taken an almost libertarian approach to government and politics: the less of both, the better. That's changing, particularly as local companies realize that governments around the world are serious about building their own high-tech industries - in essence, building the competition. Waitz says the U.S. should look at this competition as if it were the Olympics. "Who do we want to send to the Olympics? Our 10th-fastest guy?" he asks. "We want to send the fastest guy, and that's Silicon Valley."

But that "guy" also needs to be trained well: "Silicon Valley is the most capable, but [people] also assume it will win. There's no support." Government should step up to offer that support, Waitz says. It can be an active partner in Silicon Valley's retooling by helping foster new businesses and growth of existing ones via funding, tax breaks, and legislative support.

To help Silicon Valley truly rebound and flourish, many say, could also require changing its boundaries. Historically, it has been neatly defined as the area south of the 92 Freeway, including towns like Santa Clara, Palo Alto, Mountain View, Menlo Park, and San José. But if Silicon Valley is to succeed by melding disparate businesses and technologies, the map has to be redrawn, at least mentally. Companies need to think about forming alliances with those outside their own provinces, geographically and technologically. "You can't ignore the South San Francisco area if you're going to talk about Silicon Valley and the convergence of technology," says Gary Hooper, the tech industry veteran. "Some great things are going to happen because we're recognizing that Silicon Valley is really the entire Bay Area."

In fact, this convergence and expansion is already underway. In Hayward, across the miles-long San Mateo Bridge from the traditionally defined Silicon Valley, is just such a company. Inside Quantum Dot's squat, stucco building, you won't find the foosball tables, water pistols, and other play things associated with work hard, play hard dot-com businesses. Instead, goggle-wearing, white-coated lab technicians quietly examine beakers of fluorescent liquids.

Those beakers are their business. They contain quantum dots, which are nanoscale - meaning very, very small, or, in scientific terms,10 to the negative-ninth power - bits of semiconductor material that emit bright colors. "You can take these different colors of the quantum dots and attach them to biomolecules, and a research scientist can use them to visualize their experiments," says Carol Lou, the company's president.

In other words, the dots help scientists analyze what's happening inside of a cell. For instance, to see how a drug molecule affects a cell, a scientist might attach a quantum dot to a cell component, and observe how a drug affects it. It's a big step forward for researchers, Lou says. The company already has hundreds of customers, mostly university researchers and drug companies. "Right now they use dyes that are found in nature, and the problem with those dyes is that they fade quickly," she says. Quantum dots last much longer.