For $150 or less, these pint-size cameras allow people in separate locations to see one another on their computer monitors via the Web. As prices drop and quality improves, the netcams are finally reaching a mass market, widely sold in computer and electronics stores. More than 1,000 netcams are being bought every day world-wide, according to Intelect ASW, a market-research group.

The result: Grandmothers can watch their grandchildren toddling overseas. A boss at headquarters can have virtual face time with someone in the regional office.

But those aren't the applications that are really fueling the netcam boom. A great many surfers are pointing their new cameras at X-rated escapades, turning their bedrooms into their own homemade port channels.

Some are free, and some link a computer owner, who pays for the service with a credit card, with an"exhibitor." That is, a man or woman, often at home, who will perform sexually in front of a netcam for a per-minute fee, usually 99 cents or more.

Using online cameras for sex is "a huge market," says a spokesman for Logitech, a Fremont, California, company whose $100 QuickCam is one of the best-selling models. "We don't advertise the product that way, of course. But people are going to do what people are going to do."

Indeed. Two years ago, Microsoft Corp. included free videoconferencing software, called NetMeeting, in its Web browser. Thinking the service would be popular with business users, Microsoft included an option for NetMeeting users to add their names to an online directory to find other users.

But within a few weeks, people on the prowl for a cybertryst started signing in, with names like HOTMALE and STRIP4U. Frequently, so many people try to log on at the same time that the Microsoft computers used to coordinate the traffic end up jammed. The often X-rated public listings have become a bitof an embarrassment at Microsoft, and now the software giant says it is getting out of the videoconference-directory business altogether.

Netcams essentially mark the arrival, in a different form, of the long-anticipated "video phone," that blinking marvel of techno-futuristic life that was a staple of world's fairs. And with netcams, sex is again proving to be the content that propels a pioneering technology, like videocassette recorders and online chat, into wide usage, helping it gain critical mass.

A number of nuts-and-bolts developments have also contributed to the popularity of netcams. New sockets on PCs make it easier to plug in netcams. Image quality is improving because of cable-modem Internet connections and high-speed digital-subscriber lines, or souped-up copper telephone lines. And netcam prices are falling. A few years ago, the cheapest model was $150. Today, it's closer to $80.

How fast are they catching on? Consider ICUII (as in "I see you, too"), a Web site that helps netcam users findeach other. In three months, the company's customers have more than doubled, to 100,000. And that's despite a doubling of the price for the special software needed to access the site, now $30.

"It's a gold mine," says Kevin Adair, chief executive of ICUII, based in Corpus Christi, Texas.

Users often find each other through directory listings, which like personal ads, spell out the proposed rules of engagement, often in coded abbreviations, like STR8 or M4M. People who want to use their netcams to talk about other topics, like the weather, sometimes plead, "Clean Chat Only."

In the new netcam underground, many of the players are male, a problem for heterosexual men. A dearth of available women "partners" is a frequent lament in comments they post online. At the same time, many online services have thriving gay-male sections.

A growing number of Web sites, such as Ifriends.net, charge online visitors a per-minute free to watch an exhibitor, or paid performer. ifriends splits the fees with theexhibitors, who work in front of home-computer netcams.

"I was pretty embarrassed in the beginning, but it only took a week for that to go away," says a woman who identifies herself as Donna and won't give her last name. She says she quit her job as a waitress in New Mexico to become an Ifriends exhibitor full-time.

Ifriends, which started up in San Francisco on Valentine's Day last year, says it now has 1.8 million members. It handles roughly 15,000 sessions a day. With an army of 14,600 exhibitors, the company has annual revenue in the tens of millions of dollars, says Allan Hadhazy, president.

As far as legal issues go, he says, Ifriends hasn't had any problems, partly because it is careful to mind local obscenity laws. For instance, it doesn't hire exhibitors from the handful of communities that tend to prosecute adult video stores of suppliers. Neither harassment nor child pornography is allowed, Mr. Hadhazy adds.

A mushrooming number of exhibitors is changing the economics of the business forthe online performers. "In the beginning, we could make $5 or $6 a minute," says Drew, whose girlfriend is an Ifriends regular. "Now, there are so many people exhibiting that we are struggling to make a dollar."

Some of the netcam videoconferencing is far less risque. There is software, for instance, that allows people to see many online users on-screen at once, including CU See Me, developed by Cornell University. With it, a single computer screen will display several smaller screens, or little boxes showing different videoconference participants talking to each other. Among others, there are meeting sites for children, new mothers and people who want to discuss the latest movies.

Sometimes, though, uninvited -- and unclothed -- pranksters pop up on-screen in the middle of a session, "mooning" or otherwise crashing the visual chat room.

But in the fast-moving Internet world, some services have already sprung up to deal with such exhibitionist mischaps. Vidwatch.com, of Tacoma, Washington, charges$5,000 to $7,000 a month to monitor a general-purpose videoconference site and yank any offenders off the server. Surveillance is conducted by a person at Vidwatch.com who actually supervises the discussion.

"These require a human being," says Bill Towey, president of Vidwatch, "In the same way that there has to be a bouncer in a bar."

(The Asian Wall Street Journal)