A fine film of sweat on his forehead, he paces the room, clenching his teeth, jerking his shoulders, checking his watch. He is, according to his promotional material, "America's Pied Piper of Play."

Dr. Matt Weinstein is presiding over a "playfulness training" session for the American Society of Association Executives. At the society's downtown headquarters, about 60 division directors, advertising assistants, bookkeepers and such have formed themselves into groups of six to fill out questionnaires. "Who were your early models of 'adult' humor?" is one query. "Did your parents, brothers, sisters, teachers exhibit a sense of humor?"

"Timekeepers, keep things moving!" Weinstein shouts with an attention, shoppers! delivery. He blows on his slide whistle and the hubbub dies. "We need to go on to the next part now, even though some of you haven't finished. We have just 12 minutes left together. So let's have fun."

It's no picnic, teaching people to play.

Weinstein says he tries it about 60 times a year, charging corporate and college groups $2,000 a session. The employes of Playfair Inc., his company with branches in Dallas and San Francisco, travel all over the country giving $1,500 workshops. "The Use of Laughter to Build a Positive Corporate Culture" was the theme of Weinstein's session in Washington the other day.

At 36, he describes himself as an educational psychologist in the mold of the encounter and sensitivity movements. Once, while teaching a "humanistic approach to literature" course at the University of Massachusetts, he called attention to the institutional constraints in Ken Kesey's "One Flew Over the Cuckoo's Nest" by having undergraduates tie each other up.

He spent much of the Me Decade at the Game Preserve, a center for "adult playfulness" in Pennsylvania, where he learned that "if you get a group of people to play childhood games, they're going to end up at each other's throats. Most people have the wrong idea about childhood. It's an extremely violent time." He's a journeyman of the talk show circuit -- "Donahue," "PM Magazine," "AM City Name Here ," FM radio -- although once, he says, "I did a dumb thing for my career by not going on the 'Merv Griffin Show' when I had the chance."

More recently, he's served on holistic medicine panels alongside health guru Norman Cousins, whose name he regularly invokes as a fellow apostle of play. A professor at UCLA Medical School, Cousins says of Weinstein, "In a country dedicated to the bottom line, I guess it's nice to bottom out with a little humor. But he also makes me think of Samuel Morse's first message over the telegraph: 'What hath God wrought?' "

The author of two books, Weinstein is writing a third, to be titled "Putting Fun to Work." "Just look at the best-seller list," he says. "Business books and humor books. But nobody except me is doing a funny business book."

And as if all that weren't enough, he's an aspiring stand-up comic. His most recent appearance was during an open-mike night at the Comedy Corner in Dallas. "For my latest shtik," he says, "I come on as an insane megalomaniac from outer space, trying to enslave the earth."

Weinstein's approach is borsch-belt frantic -- lots of shoulder and wrist. He's kinky-haired, about 5 foot 8, with a good pair of lungs. "How many people have already confused me with Richard Simmons?" he asks.

"I know what a lot of you are thinking." Pause. "This guy had better not be boring." Pause. "Boredom is a form of slow death." Pause. "I know that after years of unbelievably boring workshops" -- pause -- "a lot of you are experts at looking like you're paying attention when you're totally out to lunch." Pause.

"I think I have a good sense of timing," he says later. "And I'm also okay with dialects."

The dialect today is Phil Donahuespeak, brimming with boisterous amiability. "I wanna share with you," he begins. "I wanna share with you a kinesthetic structure . . ." He's got bottles of warm Perrier under the lectern. He sips as he shares his message. "It's a powerful message, a revolutionary message, a message you can impact the whole world with."

This is Weinstein's message: "LIGHTEN UP ALREADY, WILL YA?"

To put it over he wields a slapstick arsenal -- the slide whistle, a rubber fish, a battery-powered ray gun -- and lets fly with a fusillade of laugh therapy. For the American Society of Association Executives, the trade association of trade associations, the therapy involves the raising of arms in triumph while yelling, "I'm depressed!"; snarling and growling like an enraged tiger; and screaming, "GET OFF MY BACK!" at an imaginary monster while smacking it in the ribs.

At first the patients respond uncertainly to the treatment, with reddening faces and downward glances. Soon these minimal responses have escalated to ripples of laughter. Before long, a woman in a somber business suit, following one of Weinstein's exercises, is jumping up from her seat to shout, "I want a standing ovation!" The others react instantly with sustained and vigorous clapping -- at which Weinstein nods and smiles.

Then there's the questionnaire. Ordered by Weinstein into six-member teams, the participants crouch in game-show huddles. "Is your present humor style at work (circle one) Disapproving? Passive? Active? Inventive?" "What is your opinion of practical jokes on the job?"

Weinstein paces, checking his watch.

"Are there any specific changes that could be made in your work environment so that things could 'lighten up' a little bit?"

He blows on his whistle. After gathering up the questionnaires, he reads off a few of the group's suggestions: "Friday morning doughnuts . . . staff happy hour at a bar . . . regular lunches between two divisions at a time on a rotating basis between divisions . . . "

And three hours after he started, Weinstein is basking in applause.

"This has been great," says Tammie Wilkerson, of the society's advertising department. "Now I'm ready to go back to work and deal with stress on the job."

"Maybe now," ventures president William Taylor, "we'll have a feeling in the work place that we're more real friends together and less just employes."

William Barcliff, head of public relations, blots his brow with a handkerchief. "This is more exhausting than work," he says.

Weinstein denies that he's a frustrated comedian, despite his occasional forays into nightclubs.

"I really like this a lot better," he says. "For one thing, I don't have to stay up till the middle of the night to deal with a hostile, drunken audience. For another, I'm financially more successful than almost every stand-up comic in the country. And for me, if all I was doing was making people laugh, that just would not be enough."