A groan goes up from the cluster of teenagers clinging to a dusty traffic island in the middle of Times Square: Apparently MTV, whose glass-walled studio they've been peering up toward in hopes of waving to their friends at home, is not shooting outdoors this afternoon. "We risked our lives just to get here and be on MTV," wails Cynthia Hempel, a 16-year-old from Connecticut, as cars and smelly buses stream past, inches from her toes.

Happily for New York visitors, however, the prospects of getting onscreen for a millisecond to wish Grandma a happy birthday or declare one's love for a TV host are about to improve.

In addition to the MTV facility at Broadway and 44th, the Fox News studios on Sixth Avenue and the "Today" show's popular Rockefeller Center location, "Good Morning America" will begin broadcasting from its brand-new, indoor-outdoor Times Square studio on Sept. 13. When Bryant Gumbel returns to morning television with CBS's "The Early Show" on Nov. 1, he'll have an almost $30 million new home with glass walls at Fifth Avenue and 59th Street, next to FAO Schwarz and across from Central Park and the Plaza Hotel. Expect to see still more people on TV in funny hats, holding up hand-lettered signs.

One could view this as democratization. "It's an empowering thing--people in suits and makeup aren't the only people on television," says Steve Friedman, who launched this trend five years ago as executive producer at "Today" and is now upping the ante as senior executive producer of the new Gumbelcast. He got the idea in the 1980s when the "Today" gang made a train excursion through the heartland and saw fans waving "Hi, Bryant!" and "Welcome, Willard!" signs in the wee hours--in tiny towns where the train didn't even stop. "People want to reach out and touch those people who are part of their lives," he concluded. Now Rockefeller Center is a tourist destination at an hour that used to belong to street sweepers.

But of course one could also chalk up TV's new passion for Manhattan streetscapes to competitive pressures. Shortly after "Today" moved into its glassy new studio in 1994, drawing everyone from lovers proposing marriage to folks dressed as hot dogs, it passed once-dominant "GMA" and has remained No. 1 in the Nielsens since the end of 1995. In addition to the hundreds of folks who show up on any pleasant weekday, "Today's" outdoor concerts on summer Fridays regularly attract 1,500 to 2,000; a Ricky Martin appearance in June drew 6,000 shrieking fans and shut down traffic. A 20,000-square-foot retail store called the NBC Experience opened across the street last spring. Small wonder that other TV people started thinking this might be a good idea.

It helped that a simultaneously rejuvenated midtown Manhattan offered a shinier, happier backdrop. Times Square in particular is more bustling and neon-blanketed and has fewer porn-flick marquees than it did even five years ago.

MTV had been there for several years before it started shooting news shows in what had been office space. "We went down and saw this spectacular view and said, 'This is the place!' and kicked this poor guy right out of his office," says MTV News chief Dave Sirulnick. The corner of 1515 Broadway became MTV's primary studio two years ago; now kids regularly camp outside hoping that dreamboat veejay Carson Daly, host of the afternoon show "Total Request Live," will let them request a video on-camera or invite them into the studio to chat. When popular musicians like Limp Bizkit or the Backstreet Boys appear, the crowds swell so alarmingly that uniformed off-duty cops are on hand.

By now, TV executives say, living-room-style studios have begun to seem somewhat static. "You can feel very isolated in a studio which has no windows," says Phyllis McGrady, the executive in charge of "GMA." When the show moves to 7 Times Square next month, the huge glass panels on the street level will swing open for cooking and exercise segments and weather forecasts. Charles Gibson and Diane Sawyer will descend from their second-story anchor desks to mingle with the masses now and again. "Maybe we'll use [passersby] as our instant poll, have them react to the news," McGrady speculates. "We have a political year coming up."

Enter CBS, determined to break its long streak in the No. 3 spot. "If you're going to rip yourself off, you've gotta do it bigger and better," says Friedman of the new studio in a skyscraper once known as the GM Building. It's now officially called the General Motors Building at Trump International Plaza, with large brassy letters spelling T-R-U-M-P in honor of its new owner. At least Donald Trump sold the Plaza Hotel years ago, sparing CBS the potential sight of T-R-U-M-P dominating the horizon above its zillion-dollar anchor's head.

The new digs will cost nearly twice what "Today" spent for its indoor-outdoor studio, but Friedman now considers such facilities "the price of admission" in the morning sweepstakes. "If one show is in Rockefeller Center and one is in Times Square, you can't be on Eleventh Avenue," he says. "Our hope is, we win the real estate wars."

CBS has negotiated to plant cameras on surrounding buildings to be able to offer "bumper shots" (leading into and out of commercial breaks) of horse-drawn cabs pulling up to the Plaza, twirling skaters in Central Park and other atmospheric scenes. " 'Today' is a small outdoor corner of Rockefeller Center," Friedman says, dissing his own past creation. "We have a neighborhood. . . . We're trying to make our show as big as possible. Big, in television terms, is beautiful."

In fact, Friedman's even willing to claim that the success of street-level studios contributed to the city's current renaissance, as much as the other way around. When "Today" took to the streets, he says, "People at home said, 'Hey, I don't see anybody getting killed there. I see people like me, having a good time.' "

CAPTION: NBC's "Today Show" started the move to outdoor broadcasts. Here hosts Katie Couric and Matt Lauer talk to Hillary Rodham Clinton.

CAPTION: CBS's plush broadcast facility in its new home at Fifth Avenue and 59th Street.