When Ben Lewis met the national beverage buyer for Whole Foods, the buyer was shocked to discover that the founder and CEO of Give Water was a sophomore at the University of Pennsylvania's Wharton School of Business. But Lewis says his age, 20, has been only a benefit for him in launching his bottled-water brand. "The youth element adds some excitement and uniqueness to the whole brand and the story," Lewis says.

Borrowing the business model of Ethos Water, which is owned and distributed by Starbucks, Lewis's company donates a share of every sale to charity. But to differentiate itself from Ethos, Give donates 10 cents per bottle sold, compared with the 5 cents that Ethos will donate. (Give's average retail price is $1.29.) Another contrast: Ethos funds clean-water programs overseas, while Give directs its consumer-driven philanthropy toward local charities in the markets it serves. And Give lets customers choose from several charitable options: Its bottles come with four differently colored labels, each representing a different cause. Sales of blue bottles support children's causes; pink bottles support breast cancer research; green bottles support environmental causes; and orange bottles support muscular-disorders research. "Consumers want choice," the entrepreneur says. "They want to choose how they give back, and they want to give back locally."

Lewis and a few of his friends had the idea for Give during high school. The summer before entering college, Lewis, who describes himself as "the 10-year-old who read The Wall Street Journal," borrowed warehouse space at a friend's dad's office and started selling from the trunk of his car. He persuaded a few delis and grocery stores in his hometown, Pittsburgh, to stock the product. Give caught the eyes of distributors, who picked up the product along the East Coast, in Canada, and in the Midwest.

In the 18 months since its debut, Give has donated more than $50,000, which suggests retail sales of about $650,000. Whole Foods is distributing the product in stores on both coasts, and Lewis thinks Give will have national reach by 2010. He hopes someday to donate $1 million a year to charity.

Conscious of criticism of the industry's environmental impact, Lewis plans to switch to new biodegradable and recyclable bottles that a company called Planet Green Bottle is launching this spring. "When we announced this technology, Ben was the first person who called us," says Patrick Rooney, the Toronto-based company's director of corporate development. "As a young guy, he's more in touch with what is happening out there. He knows consumers are demanding plastic bottles that won't be around to pollute the planet forever."

In addition to going green, Give also has plans to launch an energy drink this spring, with donations going to renewable- and sustainable-energy charities, and Lewis hopes to branch out further. "A year from now, it's conceivable that there will be 10 different causes and several products," he says. "Once we have that relationship with the customer, the possibilities are endless."

Lewis has to balance the responsibilities of being a full-time student who lives in Philadelphia and the CEO of a company based in Pittsburgh. Though Lewis often must decide between taking a conference call and going to class, he speaks with his four-person staff all the time. Mark Slepak, Give's 37-year-old director of sales, who previously worked for Red Bull and Jones Soda, says he has never seen a CEO as engaged as his current boss. On a recent day, Slepak got off the phone with Lewis at 2:30 a.m. and was back on the phone with him at 7 a.m., and Slepak says that is typical.

Lewis sees the roles of student and CEO combining to provide him with a great education. "I'm not the type of person who just wants to sit in the classroom and learn about an industry or learn about business," he says. "I want to go out and do it myself. That's what Give allows me to do."