When the idea surfaced in the mid-1970s, it sounded like a sure-fire winner. Instead of flying to faraway meetings, busy corporate executives and convention-goers could save time and money by meeting electronically: People in one city would gather in a special room and have televised meetings with people in other cities.
Such ''video teleconferences,'' however, didn't really catch on. High costs and traditional business habits - people like doing their handshaking in person - have prevented the technology from becoming the revolutionary communications tool early boosters had predicted.
Now, however, there are signs that teleconferencing may be ready to take off. No one is predicting (again) the surrender of the gavel-thumping convention hall to the Video Age. But dipping costs and new technologies are boosting the number of companies and groups turning to it for meetings, sales sessions, and other presentations.
''We are seeing a shift in business attitudes,'' says Christine Olgren, an expert on the subject at the University of Wisconsin. ''More people are trying it out.''
Indeed, the fastest area of growth may be the so-called special-event video conference. These are one-shot affairs, usually held for such things as introducing new products, training employees, or explaining sales strategies.
Some 300 such meetings were held in the United States last year. This could jump to 500 this year. They have been popular among associations and businesses interested in reaching audiences without a need to invest in permanent facilities (here rooms for televising the event are either rented, or else an outside ''producer'' provides the equipment and arranges the meeting).
In September, for example, in an attempt to fire up sales troops and pitch a new book, Mary Kay Ash of the cosmetics company that bears her name beamed a message to some 100,000 workers at 75 sites around the United States. Some politicians have used teleconferences for fund raising. A few companies are recruiting workers on college campuses via TV. Even some religious organizations are using satellites to stay in touch with far-flung congregations.
The idea of conducting face-to-face meetings with someone on the other side of the world is at least as old as broadcast TV itself.
At the 1964 World's Fair, AT&T unveiled its Picturephone, which allowed a person to see as well as hear someone on the other end of the line. It drew curious crowds but turned out to be a commercial dud.
Today's video conferences are an extension of the same idea. A ''live'' TV broadcast is beamed, usually by satellite, between electronically connected rooms. Images and voice can be carried both ways between sites (two-way video). Or the pictures can be blinked from one site to many locations (one-way).
The market for such ''telemeetings'' has been growing modestly. By one estimate, some $80 million in video teleconferencing equipment and services will be sold this year.
Meanwhile, Frost & Sullivan, a New York market-research firm, has estimated that fewer than 10 percent of the largest US corporations have conducted video meetings. But about half surveyed said they expected to use the technology in the future.
How soon they might will hinge partly on costs, which are dropping. Until recently, a group wanting to set up its own system had to shell out $400,000 to of the special high-capacity circuitry needed, were another $1,600 on top of that for a one-hour, coast-to-coast meeting.
Stiffening competition and new equipment are changing the equations on both fronts. A long-distance video call is now down to about $750 an hour. Private conference rooms can be built for $250,000, and new portable and ''modular'' systems are being pitched by vendors.
But the biggest savings, at least in transmission fees, are likely to come when engineers devise a way to compress the video signal enough so it can be sent over standard telephone lines. A California company, Widcom Inc., has come out with equipment that will do just that. Other companies in the US, Europe, and Japan are working on similar technology.
This ability is also leading to a revival of something resembling the original Picturephone: desktop models that will allow one person to have a televised conversation with someone else without the need for going to a special room.
AT&T is expected to announce soon a service that would make possible dial-up video conferences between people who have this equipment.
There is a snag with compressing signals, though. Because they are transmitted at slower speeds, motion appears choppy or blurred. For this reason, the first use of such systems is likely to be confined to transmitting relatively still images and charts and graphs.
Video conferencing, in general, isn't likely to produce radical changes in the way corporations and other groups conduct business. Costs continue to scare off many. So does human resistance: Many managers still prefer personal contact. Others don't like the way people appear on screen. They're expecting affable Johnny Carsons but instead see fellow workers who look like they're giving their first book report.
''The fundamental problem is that the technology which exists today doesn't fool people into believing a person is in the same room with them,'' says Kenneth Bosomworth, president of International Resource Development Inc., a Norwalk, Conn., high-tech consulting firm.
Still, use of the technology may begin picking up. Elliot Gold, president of the TeleSpan Publishing Corporation, a business communications consulting firm, predicts that twice as many corporations will hold two-way meetings via television this year than last.
''People are getting more comfortable now with the technology,'' says Rob Hallam, director of marketing for VideoStar Connections Inc., an Atlanta-based firm that sets up special-event and other teleconferences.
''We are beginning to see it really catch on as a very effective alternative to being there,'' says Peter de Tagyos, district manager of teleconferencing at AT&T Communications, the long-distance and international arm of American Telephone & Telegraph Company. ''This may just be the next best thing to being there.''