Matt Damon is both a hot Hollywood actor and a water wonk.
The man who brought Jason Bourne to life spends considerable time these days preaching the virtues and value of getting drinking supplies as well as "the dignity of a toilet" to the world's needy.
Affable by appearance and as soft-spoken in person as he is on screen, Damon gets stone-cold serious when he talks about the issue.
"Having traveled in the Third World quite a bit, I started to get a real appreciation for the magnitude of the water crisis, and it just shocked me," Damon said during a media reception at the World Economic Forum in Davos, Switzerland. "Every 20 seconds a kid dies because they lack access to clean water and sanitation."
(Read more: Pope challenges Davos elite to aid inequality)
Damon has brought an extra element of star power to a conference that for 44 years has gathered top thinkers, policymakers and, on occasion, a celebrity or two to devise solutions to the world's problems.
He spoke to reporters used to seeing bold-faced names in these parts—"this is the calmest room I've ever been in," he quipped—who nonetheless were deferential and even joked with him about whether he would show off some of his "Bourne" moves on the famed slopes of the Alps. (Nursing a broken collarbone and leaving a wife and four children back home, Damon said skiing wasn't in his plans.)
For the most part, though, the tone was serious.
Rather than make simple pleas to throw cash at something in hopes that it will go away, Damon is willing to speak the language of Davos.
(Read more: Richest of the rich ponder how to level the field)
That brought the fairly informal chat around to the concept of "water credits"—essentially a form of microfinance or peer-to-peer lending that provides money to the water-deprived so they can fix their problems and move on to healthier lives.
"As I started to study the issue and realized how complex it is, I realized that charity alone—digging wells—we're never going to dig our way out of this," Damon said.
Consequently, he looked for expertise and found it in the form of Water.org, an organization he co-founded in 2009 with Gary White, formerly of WaterPartners.
(Read more: Bill Gates: There will be no poor countries by 2035)
Almost all of the 250,000 or so loans involved with water credits have gone to women, something that stands in contrast to the hugely male makeup—85 percent—of the Davos attendees.
"Because this particular group of people (in Davos) are so influential but they really respond to ideas like this, it's something that's not a handout it's a hand up," Damon said. "It's really about seeing the world's poor as citizens of the world and customers."
—By CNBC.com Finance Editor Jeff Cox. Follow him on Twitter @JeffCoxCNBCcom.