The Saturday Evening Post no longer arrives in the nation's mail boxes; it makes its way indoors through the TV screen each week on George Schlatter's "Real People." The NBC series that is loved by no one except the public is not only the Saturday Evening Post of its time, but also the Life and the Look, the "March of Time" newsreels and Pete Smith's old shorts.

"Real People" can be as shamelessly corny as a Norman Rockwell cover, but then, like those covers, it can also hit home in a blunt, beguiling, universally accessible way. There is probably less distance between "Real People" and its audience than there is with any other prime-time network television show.

And it all flies by as the most concentrated kinetic assault ever on the air for more than 30 seconds at a time; it's a cross between a magazine and a picture flip-book. Tonight at 8 on Channel 4, "Real People" celebrates itself and the city of New York -- or some fanciful, smile-button version of New York -- with a stunning and spectacular 90-minute special.

About 20 minutes of it consists of material seen on previous shows that has been ruthlessly edited into blitzy montages. Back again are such surreal people as Kelly Everts, who "strips for God"; Animal X, who designs clothes primarily, it would appear, for transsexual Plutonians; matchmaker Dan Fields, who says his "Uncle Oiving" got him started in the business; the dauntless A.J. Weberman, who is captured on film trying to steal Nixon's garbage and then captured for real by a Secret Service man; and the pint-sized producer of a TV news show for kids. "I love power," says the kid.

An 80-year-old woman is on camera long enough to say of the elderly, "I think they shouldn't call them 'senior citizens.' Phony! If you're old, you're old." And a man so overcome with his mission as a custodian at the Statue of Liberty that he has dubbed himself "Keeper of the Flame" and says he spends his spare time writing poetry about the gal with the torch.

But the new material is the best, starting with a dizzying visit to construction workers as they rivet and swivel on steel beams 39 stories up. The segment features the show's most valuable discovery, Sarah Purcell, a living doll with brains who also gets to play shadow to New York Mayor Ed Koch in another segment, on a day in the life of hizzoner. According to "Real People," Koch is the cuddliest New York mayor since La Guardia.

"How'm I doin'?" the mayor asks Purcell as they part on the steps of Lincoln Center.

The breakneck pace is interrupted with a tasteful breather, a report on how apprentice stonemasons are being trained to continue work on the largest Gothic cathedral in the world, St. John's in Harlem. This is sandwiched between a garbage man who invented "smell art" and a flock of firemen who ski funny. But that's all right; it all fits within the program's mandate to chronicle and glorify individualism, involvement and the infinite variety of species that fit within the broad category of the human race.

Cameras wander outside Manhattan for stories in Queens and other boroughs, and those who've appeared on past shows are reunited aboard a Circle Line boat circling Manhattan. Sometimes they look understandably embarrassed by their flashes of flame, and other times they just look understandably elated. The program ends, as we know it must, with a montage to the tune of "New York, New York," as recorded by the world's greatest popular singer, Frank Sinatra.

One could easily fault the show's rosy view of New York as doggedly disingenuous -- preposterous, even -- but producer Schlatter really does think the city has turned around and found some mystical new esprit de ville. The viewpoint is put over in such a delirious and invigorating way that by the end of the special one may find oneself actually longing to be a New Yorker. Yes, a New Yorker.