Aaron Patzer lives in a 600-square-foot, one-bedroom apartment in Palo Alto with an old couch and TV. His favorite shoes are hand-me-down brown leather wingtips that, at 39, are older than he is. He gets $12 haircuts.

He drove a 1996 Ford Contour until he ran it into the ground at 150,000 miles. His new ride is a Subaru Outback that he bought for $29,000.

You'd never know that the 30-year-old entrepreneur sold his Internet start-up for $170 million in 2009 or that he is now a top executive at Intuit Inc., the financial software company.

With a few notable exceptions, Silicon Valley's rising young stars are rejecting the traditional symbols of status: fast cars, yachts, luxury homes. To make their mark, they're putting their wealth into social causes and start-up ventures.

"Wealth needs a purpose greater than big houses and flashy cars," said Patzer, founder of Mint.com, which helps people manage their money.

At 27, Dustin Moskovitz is the world's youngest billionaire, according to Forbes. He was born eight days after his Harvard College roommate Mark Zuckerberg, with whom he founded Facebook.

Moskovitz could afford any home he wanted, but he chose a condo in San Francisco. He bikes to work at his tiny start-up, Asana, which is making project management software for businesses. He leaves his Volkswagen R32 hatchback in the garage.

He says he flies coach, and he's socking away money to fund his philanthropic foundation. Like Zuckerberg, he has pledged to give away his wealth during his lifetime.

"Things can't bring you happiness," Moskovitz said. "I have pictured myself owning expensive things and easily came to the conclusion that I would not have a materially more meaningful life because of them."

Zuckerberg is another billionaire living below his means. For years, he crashed in a tiny apartment with a mattress on the floor and dial-up Internet access. He recently bought his first house in Palo Alto for $7 million, a fraction of what he could afford.

Zuckerberg, who has listed "minimalism" and "eliminating desire" as interests on his Facebook profile, drives an Acura. His one major outlay: Last year he donated $100 million to help improve public schools in Newark, N.J., among the country's worst-performing school systems.

Skeptics may wonder whether all this conspicuous self-denial is scripted. Tech titans know they score public relations points by showing a common touch — particularly in austere times.

But the evidence suggests that it's not an act, according to Alice Marwick, a researcher with Microsoft Corp. whose New York University doctoral dissertation in media studies was about social status among the Internet set.

It's not that this new generation of tech entrepreneurs doesn't seek status, Marwick said. They just seek it in different ways.

"This is not a community that values good looks, visible wealth or having a hot body. Those are not the ways that they distinguish high status from low status," Marwick said. "Technology millionaires don't hobnob with celebrities or buy a fancy car. They travel to Thailand or they fund an incubator. These things are just as expensive, but that's the classic hacker ethos that prizes the mind, not materials."

The hacker ethos is also classically male. "Being concerned with appearance, shopping for clothes and decorating your house are feminine values. Tech millionaires see that type of spending as silly and frivolous," Marwick said.

Silicon Valley measures achievement by what entrepreneurs build, not what they buy.

"You do not need to have an Aston Martin in the driveway," said Drew Houston, the 28-year-old chief executive and co-founder of Dropbox, a San Francisco start-up that helps its 25 million users worldwide store and share photos, videos and documents. "It's more important to have the freedom and the independence to build something for a huge audience."

Wealth does have its privileges. Patzer may have a television that is so old it can't stream Apple TV, a Christmas gift that sits unopened on the floor. But he did shell out $25,000 to spend a week celebrating his 30th birthday with friends aboard a catamaran yacht in the British Virgin Islands, and he's paying for his younger brother to get a degree in computer science.

Then there's Sean Parker, a driving force behind Napster and Facebook. Most people know him as the fun-loving playboy portrayed by Justin Timberlake in "The Social Network" who delivers the priceless line: "A million dollars isn't cool. You know what's cool? A billion dollars."

Parker, 31, co-founded Causes, a social networking service that encourages people to donate millions to nonprofits. He says it's his way of giving back.

At the same time, Parker has a closet filled with Tom Ford suits, trots the globe in private jets and is known to have dropped $13,000 on dinner and wine. He keeps a $100,000 Tesla electric sports car in Los Angeles and an Audi S5 in San Francisco. He has a pad in San Francisco and a $20-million, six-floor New York townhouse called the Bacchus House after the Roman god of wine.

"In certain corners, you will find excess. There's nothing wrong with people with money wanting to spend it," said Dave McClure, a tech investor and former PayPal executive. "But entrepreneurs are trying to be smarter and more frugal."

More typical, Silicon Valley insiders say, is Joe Greenstein, who last month sold his San Francisco company Flixster to Time Warner Inc. for about $80 million. Greenstein says the windfall hasn't made "a single material difference" in his lifestyle. The 33-year-old entrepreneur pays $1,000 a month for the same no-frills San Francisco studio apartment he has rented for the last 10 years.

He says he feels fortunate not to have to live paycheck to paycheck or worry about losing his job. And he gets to do what he loves every day.

"I don't feel like I live a life of sacrifice," he said. "I probably feel guilty that I don't sacrifice enough."

That was not the prevailing sentiment during the tech boom of the '90s, which ushered in a period of conspicuous indulgence. Instant millionaires bought Lamborghini sports cars and tore down small houses to build mansions.

Today's entrepreneurs who grew up in the shadow of that boom's collapse say they learned from it.

Kevin Hartz, 41, founder and CEO of the online ticketing company Eventbrite, says this time around, entrepreneurs are taking a more sensible approach to managing their businesses and their lives.

"It would be a contradiction for me to watch every penny at my company and then turn around and buy a $5,000 bottle of wine," Hartz said.

One reason many tech prodigies avoid living large is that it takes time to adjust to a sudden increase in wealth, said Edward Wolff, an economics professor at New York University who studies income and wealth. The newly rich don't know how long their good fortune will last, so they're cautious, he said.

Kevin Rose, founder of Digg, a service that helps users discover and share content from across the Web, appeared on the cover of BusinessWeek five years ago under the headline: "How This Kid Made $60 Million in 18 months."

Rose said he didn't end up making $60 million. That's just what some estimated his shares were worth.

Rose, 34, said he never bought into the hype, though he did buy a sports car (he won't say what kind) before realizing that extravagant spending "leads nowhere."

He's now working on a start-up called Milk and investing in what he hopes will be the next generation of hot companies. He spends weekends watching sports and eating home-cooked meals in his San Francisco condo with his girlfriend and their dog, a Labradoodle named Toaster.

Rose is selling the sports car and now gets around in a Mini Cooper.

"I know guys who have crazy boats and planes, and that's maybe something you do when you retire. But I don't want to retire," Rose said. "I don't feel like I have made it. Internally, I feel I have much to prove."