By Adam Lashinsky

(FORTUNE Magazine) – AMERICANS LIKE NOTHING BETTER than second acts, from politics to sports to show business. Jeffrey Skoll's previous moment in the spotlight, as the first full-time employee of eBay turned dot-com billionaire, was one of the greatest performances in the history of fledgling MBAs. But now he's casting himself in a new role: crusading movie mogul. He's out to save the world, while getting even wealthier in the process.

Skoll's vehicle is a 20-person film outfit called Participant Productions. It's got what seems to be the impossibly idealistic goal of making "socially redeeming" movies that also are "commercially viable." Sounds a bit batty, considering it's Hollywood we're talking about. Of course it can't hurt that Skoll is bringing to the project a healthy combination of high-mindedness, Internet savvy, and cash. (Last April, Skoll's 7.9% stake in eBay was worth about $3.7 billion.)

Skoll's idea is to find--and fund--feature films and documentaries that tell stories about social justice in a way that's entertaining enough to make people want to pay to see them. "Every one of our films and projects is rooted in a real-world issue," says Skoll, who is 40 and has relocated from Silicon Valley to Tinseltown.

Participant--the explicit hope is that moviegoers will participate in the issue at hand after leaving the cinema--has two features in the works with Warner Bros. Pictures (whose parent is Time Warner, parent also of FORTUNE). One, called Syriana, is a political thriller about international oil espionage, starring Matt Damon and George Clooney. The other, an as-yet-untitled film based on a true story about sexual harassment in a Minnesota iron ore mine, will star Charlize Theron and Frances McDormand. A documentary, The World According to Sesame Street, examines the effects of the kids' show in the developing world.

Participant, says Skoll, aims to make four to six feature films a year with average budgets of about $20 million each, though he's willing to "stretch" the budget as needed. His company typically will put up half the capital, making it easier for the big studios to bite down on what might not obviously be a commercial success. "It helps that I'm able to bring some of the financing, because it takes some of the risk out of the equation for the studio," says Skoll. "People genuinely want to make films they can be proud of."

Not surprisingly, the Internet looms large in his plans. Together with groups like Amnesty International and the Sierra Club, whose interests will align with the messages in its films, Participant plans to market aggressively on the web to drum up support in niche communities.

Skoll says he's well aware that wealthy outsiders historically have come to Hollywood seeking experience, only to leave with plenty of experience--and less money. But he has taken time to hire a seasoned movie-industry staff and has been schmoozing with the likes of Harvey Weinstein of Miramax. "Part of my decision to come down here was to be an insider," says Skoll. And then there's the truly pressing question: Has he met Charlize Theron yet? "No," says Skoll, "but I'm looking forward to it." Being an insider, after all, has its rewards. -- Adam Lashinsky