Craig Newmark insists that he's not changing the world.

You maybe can think of some classified advertising managers at newspapers around the country who might disagree, but he's pretty adamant about it.

Still, if you give him a minute, let him chew on the notion for a bit, the founder of the almost impossibly successful social-networking site Craigslist will cop to maybe something as socially insignificant as, oh, say, changing the way people interact.

"Maybe that's right. I just don't focus on that," he says. "Instead, well, me personally - I am speaking for myself, not Craigslist - I'm trying to help out other people who are really changing things, let's say by changing the nature of journalism or by maybe building tools for greater transparency and accountability of government."

Newmark is the Craig in Craigslist, the founder and chairman, the guy who started it all, the guy whose little adventure in Web-based entertainment listings in the San Francisco area has grown into a robust, internationally utilized clearinghouse of classified ads for almost any kind of service you can imagine.

He's as soft-spoken as his site is eclectic, the proverbial gentle giant. He'll very easily wax philosophic for 20 minutes about community and human interactions, but if you want to talk to him about the hardcore impact that Craigslist is having in the world of interpersonal communications or its economic ramifications, that's a little tougher. He won't, for example, concede that the newspaper industry is reeling from the effects of having its cash cow - the classified ads section - slaughtered, sauced and served on a bun by a site that lets you do everything from sell a car and post a job to find a pet or a party or a lover.

"That's mythology," Newmark insists. "Somebody produced a report with some guesswork, and a lot of people have taken it as dogma. We are affecting newspapers, but in general the newspaper chains are making a great deal of money now - partly, I'm afraid, because they're firing investigative reporters.

"But the newspapers have more to fear from aggressive, specialty job sites like Monster or sites like AutoTrader, which are aggressively going after business," he adds.

Craigslist President and CEO Jim Buckmaster seems to agree. Buckmaster, who Newmark is quick to point out is the managerial force behind the site, was unavailable for inclusion in this article. But in a Q-and-A-formatted story in the July 26 edition of Fortune magazine, Buckmaster talks about just how nonaggressive Craigslist is. And about how that seems to be working for the company.

"We operate with a public- service mentality such that we don't think in terms of competition ... " Buckmaster said. "During the dot-com boom, we were derided for our noncompetitive approach. But of the hundreds of Web companies founded between 1995 and 2000, we're one of only a handful that survived and prospered."

Still, there's no way this site isn't a thorn in the side of lots of media outlets. But so what, right? Craigslist is doing exactly what it set out to do - even if, at the time he set out, Newmark really had no idea what he was doing. And he certainly had no idea that 12 years later, there would be a Craigslist in 450 cities around the world, with more on the immediate horizon.

You know the story; everyone does. It's as old as time itself: Boy wants to give people an easy way to figure out where their favorite local bands are playing. Boy starts little, local Web site to do just that. Boy becomes world famous and his name - literally - becomes synonymous with the quickly blossoming concept of online social networking.