Today, scientists at MIT are expected to launch a revolutionary 3-D printer. The technology has been around for a while, but as 3-D printers get more advanced, they’re also getting cheaper, and finding new homes — like at a new retail 3-D printing shop in Southern California.

Deezmaker lies in a mini mall in Pasadena. Inside, along its walls, sit about half-a-dozen 3-D printers. They’re small rectangular machines and inside, a mechanical arm moves back and forth.

Diego Porqueras is the store’s owner. He prints some key chains working off dimensions fed to the printers by a computer. But instead of putting ink on paper, this printer uses plastic.

“The physical printing itself starts at the spool. That’s a plastic. The plastic gets fed into the extruder,” he says.

By “extruder” he means, the tip of the mechanical arm, which looks like an extra fine pencil.

“And there’s a special motor that drives it into the hot end tip where it melts and it extrudes it out very very small, like 0.3-milimeter widths,” says Porqueras.

Once the shape is outlined, the printer fills it in with layer upon layer of plastic. And about 10 minutes later, you get a 3-D plastic key chain.

Right now, there are about half-a-dozen 3-D print shops like Deezmaker around the country. They’re mostly used by crafts people making key chains and other tchotchkes. But the promise of 3-D printing is much bigger.

“It’s a completely disruptive technology,” says Ping Fu, founder and CEO of Geomagic, a high-end 3-D software company in North Carolina.

Among her achievements, Fu invented 3-D printing software to make hearing aids — the kind that fit the shape of your ear. She says, once upon a time, a highly skilled craftsmen could make eight such hearing aids a day. “Today, a high school drop out can print a few hundred of them at once,” she says.

In five years, Fu thinks we’ll see 3-D printers in department stores. If you can’t find a pair of jeans, tennis shoes or high heels that fit right, they may be able to print one out for you.