Suppose you've become financially independent through business success, investments, or an inheritance, and can have whatever you might want. What would you do with your wealth?

It's a question millions of Americans are confronting amid a dramatic rise in affluence. The United States now has more than 8 million millionaires, and studies show that an intergenerational transfer of private wealth is under way that will amount, at the least, to $45 trillion by 2052 (and perhaps three times that).

"Never have so many people had such wealth," says Paul Schervish, director of the Center on Wealth and Philanthropy at Boston College. "How they use it is a spiritual question ... the key question of the 21st century."

It's a spiritual question, he says, because many people, no longer focused on financial security or accumulating wealth, are considering what their deeper purposes or ultimate goals are in life, and how to direct their financial resources to achieve them. Many are turning to charitable giving – with Bill Gates as the most prominent example.

Defining this "moral biography" can be challenging for individuals, and a new brand of "wealth coaches" is developing to help people sort out their values and decide how much and where to give. With more than a million nonprofit organizations in the US alone, the prospect can be daunting.

"Donors are overwhelmed, so some go into a kind of paralysis and fund what is familiar to them," says Tracy Gary, the author of "Inspired Philanthropy," who helps donors create giving plans.

Many have moved money into donor-advised funds – and received the tax benefits. But according to information gleaned from a 2006 survey of 50 leaders in banking and philanthropic services, conducted by The Bridge in Boulder, Colo., an estimated $1 trillion has accumulated in those funds and family foundations, and has not yet moved into charitable coffers.

Given the world's pressing needs, some advisers are encouraging more people to get involved in philanthropy and to give a greater proportion of their income. Despite the dramatic growth in wealth, total charitable giving in the US has stayed at about 2 percent of gross domestic product (GDP) for decades.

The Bolder Giving Initiative, which counsels individuals in determining their giving potential, recently launched a 50% League to highlight particularly generous donors. About 80 donors of various ages who have given away half or more of their net worth, profits, or income for at least three years are "going public" with their stories in hopes of encouraging others (see www.boldergiving.org).

John Hunting, for example, began receiving stock from his father's company when he was 6 years old. The firm became Steelcase, the world's largest office-equipment manufacturer, and when it went public in 1998, Mr. Hunting's windfall amounted to $130 million. He has directed $100 million into a foundation that will address one of his passions: environmental issues.

Many of today's newly wealthy are younger, like Jamie Schweser. "I grew up in the punk rock scene," he writes in his bio, and "since I was 16, I've known that if we want the world to be a fairer place with justice for everybody, we have to do it ourselves." So when his parents sold their business and gave him a cool million, he decided to give 75 percent to social justice causes, including $500,000 to the Beyond Prisons Fund, which develops alternatives to incarceration.

Not-so-rich also generous givers

The generous givers aren't always the very rich. Richard Semmler, a math professor at Northern Virginia Community College, couldn't have gone to college himself without scholarships. Today he's giving away 60 percent of his total income – something he can do "because my mortgage is paid off," he says in an interview. His values led him "to support a local charity to help my community and an international charity to help the planet."

Dr. Semmler teaches a GED course at a Washington, D.C., shelter, where he also pays for 100 meals a month. Since becoming involved with Habitat for Humanity as a volunteer, he's sponsored three locally built houses ($100,000 for the last one), given $15,000 to fix up a house damaged by hurricane Katrina, and annually supports building a home in Tanzania.

"I've seen where families lived before they were selected for a house," he says. "If you earn the minimum wage here in D.C., you can't afford much, and kids shouldn't have to call a living room their bedroom. It's very rewarding to change that."

Giving is by no means the only positive or moral use of wealth, Dr. Schervish emphasizes in an interview. For example, people can start a business and employ people, or provide better health insurance for workers, or take care of a disabled person in their family, he adds.

The dramatic growth in wealth and its potential for philanthropy has grabbed the attention of the financial-services industry, which is scrambling to provide a new kind of advice. Financial firms have engaged Schervish to talk with advisers and high-net-worth clients about the "moral biography of wealth." He's training about 400 advisers on how to ask clients the right questions.

"You're helping people 'excavate' who they are and who they want to be, and your role becomes valuable in helping them close the gap," he says. "I'm teaching a way of understanding life spiritually while talking about financial advisement and how you can add value to your clients while putting money in your pocket."

At a recent Boston College conference for leaders of nonprofits, the managing director of Smith Barney Consulting Group talked about this "changing face of financial services" and his firm's "new alliance" with nonprofits.

Fr. J. Donald Monan, the chancellor of the college, noted that the "sea change in the growth of wealth in American society" means that, for the first time, private wealth is in a position to do things only governments have done in the past. [Editor's note: The original version misidentified Fr. Monan.]

"We don't know how this is going to turn out – whether it will be constructive or corrosive," he added. "That depends on the direction in which this extraordinary wealth is funneled."

Current models of philanthropy are very donor-centered, says Ms. Gary, whose great-grandfather invented the dial telephone. She gave away her inheritance, and says her own history led her to work on connecting wealthy people with community leaders and activists to bring about social change.

"I grew up living in five houses, with 35 people – African-American and Hispanic domestic workers – looking after me and my family, with planes, helicopters, conspicuous wealth," she says. When she was 9, during the civil rights movement, she began to grasp "the contradictions of living that lifestyle."

Studying with Joseph Campbell at Sarah Lawrence College, "I had to think about who I was and what it meant to be a wealthy, white, WASP woman in America in 1973," she adds. She took more interest in what her economic class was doing. "Most giving was about social networking, giving to peers, going to parties, and doing a certain amount of noblesse oblige."

Donation, but also involvement

Concerned about what she considers too great a gap between rich and poor in a democracy, Gary is bringing people in the community with "entrepreneurial, creative, and wisdom capital" together with herself and others who have "financial and influence capital.

"Together we are much richer in what we can co-create," she says. For instance, Houston has some 99,000 millionaires, and this summer she'll take a few of them on site visits to worthy nonprofit programs.

Today many philanthropists want to be involved with groups they fund. The Bolder Giving Initiative is the project of Christopher and Anne Ellinger. Christopher received an unexpected inheritance in his 20s and, cautious by temperament, he says he "wasn't going to make any decision for at least five years." Instead, the couple educated themselves about giving and then began doing the same for other wealthy young people, founding new organizations and publications.

"People want to be engaged, not just write a check," he says. Concerned about cutbacks in the arts, they've given money to projects involving theater arts in community development, in which they personally participate. "My life has totally changed through the choices I've made," he says. "Initially I was thrown when so many people knew I had money, but it forced me to get my act together ... and get to do work that I love."