(FORTUNE Magazine) – I spent two summers at Camp Mont Shenandoah. I slept on a bunk, rose at taps, and passed the days picking blackberries and competing against the Greens (I was a Buff). The highlight of the summer was a dance with the Camp Maxwelton boys.

But times have changed--the Net trumps nature--and so have girls' camps. Which brings me to a parlor at the Dana Hall School in Wellesley, Mass., where

25 teenage girls have begun breaking down the fixed and variable costs of a fictitious business they plan to launch. This is day three at Camp Startup, a two-week summer program for aspiring businesswomen. Rather than roast marshmallows, these campers write business plans, liaise with entrepreneurs, and take golf lessons from an LPGA pro.

Right now they're brainstorming a plan for Be My Brownie, a bakery a la Mrs. Field's. Camp director Valjeanne Estes blows whistles and tosses Hershey's kisses at campers who correctly use "biz words" (product business, service business) from their workbooks. "We do use sugar as a motivator," whispers camp administrator Barbara Dowd.

The girls plan to bootstrap startup costs with someone's mom's car, a used display case, borrowed cooking pans. But they have to hire a brownie baker. Counselor Pat Stanton-Rose, a Lipton sales exec, appears out of nowhere in a baker's outfit, asking for $15 an hour. (She gets $7.20.)

Camp Startup is run by Independent Means, a Santa Barbara outfit that promotes women's financial autonomy, and the goal here is to teach girls business leadership. After brainstorming and number crunching, the girls break into teams. Twenty-four hours later, the teams offer a preliminary look at Be My Brownie's business plan. Their marketing hinges on a simple premise: "They'll like our brownies, because everyone has a sweet attack now and then," says marketing exec April Wall, 14, of Durham, N.C. Management goes over planned hires: "Our VP Marketing will come from Nike; our VP Finance will be a former Fleet stockbroker," says Cali Teceno, 17, of Westboro, Mass.

The first signs of trouble for the startup come out of Finance. There's a budget for marketing and operations, but nothing for new hires. "What about Management? We need money too," says Donere Williams, 18. Barks Finance: "Well, you didn't ask us!"

Those are minor hitches. The girls still have ten days to work on the plan--about as long as your average Internet company launch--and they're serious about business. Typical is Brooke Jabara, 17, a bespectacled blonde with braces who peppers sentences with terms like "cash flow" and "customer care." Over cafeteria ravioli she reveals the source of her knowledge: "I read the Wall Street Journal every day."

Before I leave, Brooke rushes to give me her business card. I tuck it in my purse next to some CEOs'. Rather than a dull corporate logo, Brooke's card is bordered by optimistic rainbow stripes. Too bad "rainbow.com" is taken.

--Jane Hodges