(FORTUNE Magazine) – Molly Lowe, Raysa Rodriguez, and Kimy Tolentino frequent a Website for teens called bolt.com. Sometimes they also help out, cluing in the editors and posing for online catalog photos at the site's New York offices. One day a reporter who's hanging around asks why they like the Internet.

"It's all about staying connected," says Kimy, 19. His friends agree. "I'm an AOL junkie," says 15-year-old Molly. "When I was on vacation, I asked people if I could use their laptops, just to check my e-mail...."

"I do that too!" Raysa, 17, says.

"Omigod," Kimy concludes.

Welcome to teen life, Internet-style.

As parents know--and businesses are figuring out--kids are avid Netheads. According to Teenage Research Unlimited (TRU), a Chicago market research firm, 81% of teens use the Net. Kids use it to research, download photos, and shop. They also go online to read up on and chat about stars--over three months last year, kids posted more than two million Leonardo DiCaprio-related messages (that's one every ten seconds) on America Online.

Unlike adults, kids use the Web in a kind of turbo mode, juggling surfing with other activities. "They're adept at multitasking," says Michael Wood, director of syndicated research at TRU. "They're online, but they're listening to music and watching TV at the same time." The same goes when they indulge in their favorite online activities of all--exchanging e-mail and real-time chatting with friends. "You can have 1,000 different chats at once," says bolt.com's Molly, exaggerating only slightly.

Businesses want to move teens from chatting to online shopping. Wired minors will one day pack a huge economic punch. Even now they're more likely than adults to use the Internet to research the products they buy in brick-and-mortar stores. Says TRU's Wood: "When teens want information on a brand, they turn to the Internet first."

The information teens gather can be crucial to pretty big purchase decisions: Some 56% of the girls polled by Seventeen magazine said they helped their parents buy PCs; nearly 30% said they offered advice on features ("such as RAM," Seventeen's report adds, helpfully). "The companies who market computers ought to talk to the people who really understand them," says Seventeen publisher Lori Burgess, who hopes to attract PC advertisers to the magazine's site.

Already outfits like Levi's, catalog retailer Delia's, and Skechers, an urban shoe chain, are all placing spots on teen-oriented sites. Retailers are also getting creative on their own Websites. Girls who find a cool item on Delia's site will be able to put it on a Wish List--a gift registry for the Dawson's Creek crowd. And get this: At bolt.com's store, Mom and Dad can soon post an online allowance for their kids.

Back at the bolt.com office, Raysa, who's had Internet access at home for only a few months, says she likes to look at HTML source code to see how her favorite Web pages are put together. (English translation: She studies how they're programmed.) "If I see a cool blue," she says, "I look at the HTML, and I go, 'Oh! So that's how you make that color!' "

Talk turns to the band Korn, raves, and whether making money from your personal Website is cool. Periodically Molly and Kimy tune out to look at a glowing monitor where five or six e-mail windows are open. The reporter, twentysomething, begins to feel kind of old.

--Eryn Brown