The San Francisco-based designers are travelling the country with their Design Revolution Roadshow, a nationwide tour that showcases recognizable products that have been altered and designed with practical and innovative improvements. The duo stopped at Wilmington High School on Friday morning to present these ideas and products to a group of middle and high school students.

Inside the trailer, there’s a straw that filters water while you drink it, and a handheld cell phone charger powered by the wind.

There’s a wheelchair fitted with rugged and durable tires for countries where dirt paths outnumber cement ones.

There are eyeglasses that, with the turn of a dial, can change prescription depending on the wearer.

If these all seem overly practical, then that’s exactly the point.

“This approach to design is about surveying what’s been done by designers, seeing what’s been lacking, and then working to improve upon that design,” said Pilloton, who used that reasoning to found Project H Design in January of 2008.

Together with Miller, an architect and West Virginia native, as well as a core group of designers, Pilloton is trying to apply new methods of thinking about the way a product is made.

“Most product designers create gadgets and gizmos,” she said. “What you learn in design school is cool ways to solve problems, and then you get into the industry and you totally lose that. Project H was founded out of that frustration.”

The 40 items featured in “Roadshow” are taken from a collection of products that Pilloton assembled for a book, “Design Revolution: 100 Products That Empower People” which was published in September 2009.

The couple has travelled 9,000 miles and counting since February, visiting 36 schools and presenting to more than 4,000 students. Every stop is different, Pilloton said, and every group is unique.

“We’ve done everything from Stanford University to Main Street in Savannah, Ga.,” she said. “It’s totally across the board. Sometimes we present to the design department of prestigious universities, other times it’s high schoolers or tourists walking by.”

Miller and Pilloton met in San Francisco two weeks after Project H was started, and they began working together immediately. Miller had previously spent six months in Uganda with Architecture for Humanity, building a school for children orphaned by AIDS. So it came naturally that their first project as an organization, in April of 2008, would be focused on the Third World, building and delivering water transport devices called “Hippo Rollers” in a South Africa community. The products resemble an overturned barrel, with a lawn mower-like handle which allows the user to roll the water rather than carry it.

“That was our first big project,” Pilloton said, “before we knew what we were doing.”

They raised $10,000, built 100 rollers and spent two months in the country delivering them to villagers.

But not all of their work is focused on the developing world. They designed a compost system for a sustainable farm in California. They built classrooms for a community in Bertie County, the poorest county in North Carolina.

“It’s more challenging and it demands better design to work within incredible restraints,” Miller said. “It’s rewarding because it’s harder.”

Pilloton and Project H have been featured in the New York Times and GOOD Magazine, and she was recently interviewed on the “Colbert Report.” She was a 2010 fellow at the annual PopTech conference in Camden, Maine, where she met Wilmington natives Mark Rembert and Taylor Stuckert of Energize Clinton County, who were also fellows.

“(Rembert and Stuckert’s) work was really inspiring to us,” Miller said. “They are actually a part of our presentation, what they’re doing here in Wilmington.”

There is one more stop on the Design Revolution Roadshow, at Oberlin College on April 18.

And after that?

“We’re moving to Bertie County,” Pilloton said, speaking about the North Carolina community where they built new schools. “They loved what we did there, so we’re going to stay for a while.”