Morino, who made a fortune in software before retiring in 1992, is both a grant-maker through his Institute and a thoughtful observer of the new philanthropy. He points to several ways in which the baby billionaires differ from their well-endowed predecessors.

Start with the obvious: The tech elite have both money and time. Having made their bundles at 30 or 40, they'd like to see some results before they join the choir invisible.

"The new money has made people able to do things at much earlier stages of their lives," Morino says. "You have more people looking for social impact in their charitable giving, and the expectations for movement and change differ from any preceding generations. People want to come in and see results yesterday."

One senses that impatience in Todd Wagner. Along with buddy Mark Cuban, who now owns the NBA's Dallas Mavericks, Wagner co-founded Dallas-based in 1995. Four years later, the partners sold the streaming-audio business to Yahoo! for almost $6 billion in Yahoo! stock. Like Kanter, Wagner found his social conscience emerging once his paycheck worries were over. "What happened to me is just not available to a large segment of the American population," he says. "Eighty percent of the people couldn't do what I did because they didn't get to go to college and law school and open the doors. Sure, I'm proud of what I did, but there's an element of luck and an element of responsibility that goes with it."

That sense of responsibility led Wagner to focus on the so-called "digital divide" that leaves many minority citizens ill-prepared for careers in technology. But Wagner didn't think traditional philanthropic organizations offered the best chance to bridge the chasm between the clicks and click-nots.