Right after the doors open at Port Discovery, the children's museum on the fringe of the Inner Harbor, antsy patrons line up on the faux boulevard inside. They pinch each other's FUBU shirts. They fidget with the zippers of their brand-name jackets. They lean back and forth in their Timberlands.

This is young America and they are eager to run, releasing the energy that experts say the under-12 generation needs to channel in some positive direction. And the main question a year ago for the organizers of Port Discovery was whether their intricately designed interactive museum would become one of the options.

The results so far show that children who have the choice of video games, action movies, storytelling hours, arts-and-crafts sessions and spring, summer, fall and winter soccer have found something to hook them into this environment. Since its opening last Dec. 29, more than 400,000 visitors have paid to walk through the cavernous building, whose exhibitions are a collaboration of Walt Disney Imagineering and other youth and entertainment specialists. Only one-fourth of those customers have been in school groups, which means the museum is drawing more individual than orchestrated traffic. One outcome, however, has been that the bulk of the visitors arrive late in the afternoons and on weekends, clustering that has led to crowding, waiting and complaining. Some days the 80,000-square-foot museum never closes. Since September the staff has sponsored sleepovers, and 336 children have signed up.

What adults and children have found at Port Discovery is a series of activities, both physical and mental, that are organized along different topics, much like the typical museum. Except almost everything is made to be touched--or banged on. The design, with its outrageous bright colors, plenty of nooks and crannies, workshops and room-size puzzles, was meant to knock any boredom out of a trip to a museum that advertises itself as being about dreaming and creativity.

In Miss Perception's Mystery House, visitors walk through a series of hilariously jumbled rooms to find a missing family member. In Adventure Expeditions, they step into the age of the pyramids, maneuver through cavelike rooms and try to find a lost pharaoh's tomb. Hieroglyphics are part of the challenge. In the television studio, where a small Maryland Public Television station broadcasts only to the museum, a game show borrows goofy tricks from commercial TV--gongs, tossing balls through a net. The goal of "The Money Game," however, is to think about cash and decide whether to pocket it or spend it all at once.

"We have always questioned what is the work of a museum," says Kathy Dwyer Southern, Port Discovery's president since the planning stages, standing near one of the billboards promoting heroes--this one being surgeon Ben Carson. "And our response is education because skill development is something they all need."

Aware or not of the adult game plan for pushing creativity or releasing energy, the children have come. James Blucher Jr., a power-tool repairman, is watching his son dart in and out of a session where the children are making masks from recycled materials. "I have been really impressed by the safety aspects of things. There was a lot of attention paid to details," he says, touching the rounded corners of a banister. His son, James Blucher III, an 8-year-old at Medfield Heights Elementary in Baltimore, is on his first trip to the museum. He says he is having fun constructing the mask but can't take his eyes off the tower of ropes, bridges and tubes rising through the center of the museum.

"I never saw a thing that big before," says the young Blucher. That's the point. KidWorks is an enormous jungle gym that resembles a five-story building and includes a rope bridge three stories high, a tension wire to slide down, and time-sensitive games. More than 80,000 people have tried the zip line.

So what worked, and what didn't, as Port Discovery tested new approaches for children's museums? The project was under special scrutiny because of its association with Disney and consultant Michael Spock (son of the legendary baby doctor), its particular twist on the hands-on youth museums that are enormously popular across the country, and its proximity to one of the best-known family attractions in the country, the Baltimore aquarium. "We tried to infuse the idea of a story and a concept into an environment, and that is much different from what children's museums usually do," says Rob Bald, an exhibit designer and a member of the original Disney Imagineering team.

In the first year, just over half the visitors have come from Baltimore. Washington visitors account for nearly 17 percent. And the place has been the site for private events with Queen Noor of Jordan, Olympian Jackie Joyner-Kersee, Vice President Gore and the new mayor, Martin O'Malley. Entertainer Marvin Hamlisch and pianist Awadagin Pratt have come by to play and talk to visitors during their appearances with the Baltimore Symphony Orchestra.

And since birthday parties are synonymous with childhood life, the museum has a spacious room for celebrations. To date nearly 400 parties have been held at the site, and even Leonard Sachs, a prominent Maryland businessman and board member, celebrated his 75th birthday right there. "My wife told me it was a party for a friend's grandchild. I had to be pulled by one ear," he says. "We didn't slide down the chutes but it was fun."

The museum staff has spent a lot of time listening and watching and then tinkering. "We have had to fine-tune our balancing act. What we have gotten better at is figuring out what everyone liked, and then making adjustments within the exhibitions," says Southern. One question was how to engage toddlers as well as teens. In the research-and-development workshop, activities range from building a wind tower to a clubhouse. "You had a work order to fill out and then had to decide what tools to use. The 12-year-olds got to use power tools, which kept them involved," she says.

Other adjustments included raising the zip cord nearly 15 inches to accommodate all the adults who were trying to use it. On busy days, time in the research lab is now limited to one hour. Visitors wanted more food in addition to a Mama Ilardo's pizza stand, so McDonald's soon will open a store next to the front door. Museum officials worked out a system of headset codes so "lost parents" could be reunited with their children in two minutes. They had to replace the material on the rock-climbing unit because it was wearing out too fast.

To keep up with repairs, the museum decided to close on Mondays between Labor Day and Memorial Day, except for school holidays. But there is one key part of the experience that Southern didn't want to change. "We have held our ground on not having a lot of text to say what to do. We want the kids to figure it out," she says.

But when guests needed some direction, the staff decided to cross-train, so the box-office people could answer the same questions as the floor staff. There has been substantial turnover in the 75-person full-time staff, with 30 percent of the floor staff changing. "There are people who just like starting museums and don't want to do the operational thing. And there are people who don't like being around children all the time," says Southern, a veteran arts administrator who just shrugs at the thought.

The income flow has met their expectations. The founders had projected $6.3 million in spending, and have settled around $5.9 million. Close to 70 percent of that comes from earned income, including admission fees and ticket sales. Adults pay $10 and children over 3, $7.50, and only the annual membership fee has gone up slightly.

From the planning days, the staff envisioned not only serving schoolchildren but establishing an outreach to the neighborhood. A series of conversations with residents and teachers from Jonestown, a low-income neighborhood right in the museum's back yard, produced some special programs. In a unique partnership, the museum is the home to a branch of the Enoch Pratt Free Library, which neighborhood children can use without having to pay museum admission. The library has issued 700 library cards in the first year, and homework sessions and computer use are organized through an after-school program.

"We have reached some of the children we don't reach in our central library or branches," says Carla Hayden, the executive director of the library system. The librarian is part of the education team with the local teachers, as well as museum programmers, and this cooperation has exceeded Hayden's expectations. "It is a model and shows how the library can step outside our walls. We are where the kids are."

Now one of the staff's challenges is keeping fresh, and one of the best ways, Southern explains, is through collaborations. This first year, the Maryland Science Center, the aquarium and the American Visionary Arts Museum have done cross-promotions and programs. Aquarium Executive Director David Pittenger says the museum was a welcome neighbor. "It is helping with the movement of tourists and school groups to the north and east of the Inner Harbor," he says.

For three months starting Jan. 14, the museum launches a series of Mars-related activities with NASA's Goddard Space Flight Center as part of a larger public-private Mars Millennium Project. Port Discovery will host "Journey to the Red Planet," an interactive exhibition from the Crayola Factory in Easton, Pa., and sponsor daily workshop activities on drawing a constellation or making exploratory equipment, such as a control module, in the museum lab. On weekends NASA scientists who are directly involved with the Mars program will be at the museum. "The kids will be asked how do we get ready, how do we travel to Mars and what will it be like," says Southern.

On a walk through the museum, it's clear that those early-morning arrivals have been joined by dozens of others. The noise is deafening. Southern pauses by a series of lockers where the coats are tumbling all over the floor. "We need more coat room space," she says. "Does the place turn out perfect? No, but we're working on it."