Writer Ned Vizzini, 23, called from his bicycle to say that he would be late for an interview at Cedar Tavern, a bar on University Place – once a kind of writers’ clubhouse for the likes of Frank O’Hara, Jack Kerouac, and Allen Ginsberg. “I just got into an altercation with a guy on the Brooklyn Bridge,” he panted. “But I’m on my way.”

When he walked in 15 minutes later, he looked disheveled but presentable (“I’m the only guy in the city who wears Prada shoes to bike”),and with an anecdote possibly worthy of his next book. “There was a guy walking in the bike lane” on the bridge, he explained. As he drew closer, he realized that the man was “not just oblivious, but antagonistic. As I rode by, he sort of fake-punched my bike, and I was like, what the f-?” Mr. Vizzini got off his bike, quickly realized that the man was deranged, and pedaled off.

To calm his nerves, Mr. Vizzini pretends to smoke – he holds two fingers up to his mouth and dramatically drags on a nonexistent cigarette. Settling into his seat with a Jack Daniels and Coke, he sucked through his fingers like a seasoned air addict.

It’s the perfect tic for a writer who addresses teenagers with the hip-yet responsible authority of someone who has only recently entered adulthood himself.

He published his first book, “Teen Angst? Naaah…” (Free Spirit), when he was just 19, based on essays that he began writing for the New York Press as a 15-year-old Stuyvesant student. He gives the Press credit as “the newspaper that made me want to be a writer and the newspaper that actually published me.” Mr. Vizzini happened to pick up a copy of the paper as a young teen. Its contents transformed him. “I had never read a mature confessional essay before, and that’s what they brought to the table…It blew my mind.”

Miramax published his second book, “Be More Chill” in June of this year, came out with a second printing in August, and recently bought the film rights to the novel. The movie is being developed by Chris and Paul Weitz, who directed “American Pie.”

“Maybe the writing world is different now,” he mused, as though he got his start 50 years ago rather than eight. He sounds sweetly amazed at how easy success came for him.

“In 1996 I wrote a 5,000-word piece and just sent it to the slush-mail address at the front of the paper.” He waited patiently to hear from an editor. “Two weeks later, my submission comes back ‘not enough postage,'” he laughed. After a second trip to the post office and several months of waiting, Sam Sifton, who is now the dining editor at the New York Times and was at the time an executive editor for the Press, called. “He said, ‘This is good, but it’s too long.'”

He tightened it up – and began writing about once a month for the alternative weekly.

A few years later, a reflective piece he wrote for the New York Times Magazine grabbed the attention of Free Spirit Publishing, an independent publisher in Minnesota. The press wanted him to put together a book.

“I made an important decision,” Mr. Vizzini said. “The stuff I was writing at the time had curses; I was trying to be urban and gritty because I was trying to be like my idols.” He waffled over whether to clean up his prose in order to market the book.

He has since realized how fortuitous the decision to write for young adults was. He receives frequent e-mails from his teenaged readers, who “aren’t angling for a blurb,” but are genuine fans.

“It’s very nice to get mail from boys, because teenage boys aren’t supposed to read,” he added, referring to the publishing world’s assumption that young adult novels won’t sell unless they appeal primarily to girls.

Writing for young adults has also given him entry into a genre where there is real room to experiment. “Literary fiction is so clogged,” he said. “Every three months, another book comes out depicting a blurry girl running…I wanted to be that, but my first book was called ‘Teen Angst…Naaah’ and it’s canary yellow.” He laughed. “It’s true to my dork roots.”

If the packaging of “Teen Angst” whispered to dorks, “Be More Chill” is a direct missive to them. The novel tells the story of Jeremy Heere, a nerdy high school student who ingests a pill-sized supercomputer called a “squip” that makes him cool.

Miramax has taken its marketing campaign for “Be More Chill” to teens’ prime hangout – the Web. Readers who Google the word “squip” will find a neighborhood of sites that discuss the novel’s imagined universe in exceedingly earnest tones. They’ll find a National Squip Board, “insurance for the Squip life,” and a supposedly anti-squip backlash site.CelebritySquip.com posits that Ashton Kutcher must have taken the pill because “a dork like that cannot get Demi Moore without a squip.”

Mr. Vizzini knows firsthand about true high-school geekiness. At Stuyvesant, he was an avid player of Magic, the role-playing card game beloved by black-clad males in high schools across America. He went on to receive a degree in computer science at Hunter College. “When you finish, it works,” he said of working on computer programs. “No one can say it’s too wordy or it’s not the right tone.”

By now, however, Mr. Vizzini has transitioned from screen-ster to scenester – just like his book’s hero (and like many of those smart introverts everyone knew in high school). He hosts a biweekly reading series at the Park Slope bar Barbes at which audience members are quizzed about their knowledge of the readers’ works, and regularly hops around to readings at KGB Bar, Happy Ending (“the best”), Pete’s Candy Store, and the Half King (owned by another writer, Sebastian Junger). At Cedar Tavern he bumped into Jennifer De-Meritt, the curator of yet another reading series. (Mr. Vizzini complimented her by saying that her dress “would have made a good Windows background.”) He will host a screening of the oozing-with-indie-cred cult film “Donnie Darko” at the Brooklyn Brewery on September 23.

Meanwhile, he’s at work on yet another novel, about the economic pressure on teenagers to own status items of technology and clothing. It will likely be his last work for teenagers, since, as he said, “the kids who like my young adult novels don’t want me to do young adult forever.” He laughed, “I’m washed up!”