For independent filmmaker Walter Gottlieb, three minutes can last an eternity. On a Monday morning in late April, Gottlieb stares at two computer monitors and a television screen inside a downtown Silver Spring editing suite. Two years worth of tape on the restoration of the Silver Spring B&O Railroad Station flash before him. The task at hand: culling a three-minute vignette about the refurbishing of the station's clocks that will be tucked into the final product -- an hour-long documentary for public television.

Eric Camp, Gottlieb's video editor, lets footage of an interview with a clock restorer roll for a couple of seconds at a time, while Gottlieb types the dialogue into a script. When he is finished, he and Camp move onto the next blip. And so it goes, in fits and starts, for more than an hour. When they see the clock restorer look up at the finished timepiece and say, "It's back to life again," Gottlieb snaps his fingers.

"That's the one," he says. "That can be the ending, right there."

Given his subject, Silver Spring is a natural location for Gottlieb's three-man company, Final Cut Productions Inc. But he didn't move his office there until 2000, when he heard Discovery Communications Inc. was coming. "I thought, 'This is the time to take the plunge,' " recalls Gottlieb.

He ended up subletting space inside Silver Spring Studios, a production house formed by "America's Most Wanted" host John Walsh and the show's executive producer, Lance Heflin, who were drawn by Discovery, too. Other film and video-related subtenants soon trickled in, creating a miniature version of the nonfiction television and film hub that Montgomery County boosters had envisioned for Silver Spring.

For small production and post-production houses, having a major cable network next door can feel like being closer to the big time. "[Discovery] has put Silver Spring on the map in our industry, and that alone raises the profile of this entire production community," Gottlieb says. "It's the cachet of being in Hollywood, rather than Fresno."

Many of Gottlieb's colleagues share his belief in geographic synergy. Some of them, however, are finding that being in the center of the documentary filmmaking universe can also feel like having their nose pressed up to the glass.

"We thought it might help [being close to Discovery]. But it turns out that Discovery has its own post-production facility," says Jennifer Ferguson, production manager for Silver Spring Studios, which rents video and audio post-production facilities. Silver Spring Studios has also tried pitching shows to a few Discovery channels. But so far, Ferguson says, they've have had better luck with Court TV and Fox.

"I adored Discovery. I wanted to work for them for years," says Ben Howard of Howard Mediaworks, another subtenant at Silver Spring Studios. Two years ago, he got his wish. Then one of his contacts at Discovery quit. Another died. And he found himself "out of the loop." Whereas he used to refer to Discovery headquarters as "the mothership," lately, he's taken to calling it "the Evil Empire."

"Docuwood," it turns out, is not so different from Burbank. Success boils down to face time.

For former Discovery producer Dirk Hoogstra, networking is as simple as a trip to Panera on Georgia Avenue. "I always run into people over there," he says.

So far, Hoogstra's connections have helped his new employer, Brainbox Productions Inc., land producing gigs with at least two Discovery networks.

Hoogstra doesn't just know the right people, he knows his pitch etiquette. Someone presented a project idea to him once in a men's restroom at a documentary film festival. "People were relentless. I don't like that approach," he says.

Hoogstra doesn't mind helping out those who have trouble getting an audience with anyone but the dinosaur skeleton in the Discovery lobby. "We're getting lots of producers calling us. They don't know how to get their shows in," he says. About two months ago, Hoogstra organized a seminar to share his insider tips. He was inundated with so many requests to attend that he had to limit the session to 20 people.

Brainbox said it plans to soon launch a page on its Web site (www.brainbox.tv) where local filmmakers can send ideas. Hoogstra and his colleagues will then pick the best ones to pitch to Discovery. Hoogstra says Discovery execs need all the help they can get vetting pitches.

"They have to shrink the production universe," he says, lest they be overwhelmed by "the sheer workload of opening the floodgates. . . . Everybody wants to produce. There's more producers than there is work."

Walter Gottlieb is part of a wave of independent nonfiction moviemakers who have moved to Silver Spring.