It's no secret that tech is forcing libraries to change. A public service that primarily lends physical books seems almost quaint in a world where you can download hundreds upon thousands of books from Project Gutenberg and search through an almost unfathomable amount of data via Google. So libraries are bringing in e-book rentals, computers loaded with graphic design programs, and yes, 3-D printers to maintain their digital street cred.

Nicholas Kerelchuck, manager of the recently opened Digital Commons at the Martin Luther King Jr. Memorial library in Washington, D.C., calls their 3-D printer the "rock star" of the space. The library runs two to three "intro to 3-D printing" programs per day, and plans to purchase another unit soon.

Kerelchuck describes the 3-D printer's popularity as a boon to the library, but also a substantial benefit for library patrons. "They're learning math skills, engineering skill, hard science skills," he explained, adding "this is future job experience. I think that in 10 years if someone has experience using a 3-D printer, they are far ahead of the curve."

Since the technology is so new, Kerelchuck says, "there's no rep coming" to train them on the machines, and the staff has figured out a lot of it on their own. They also relied on the experiences of other public libraries to determine the best way to roll out the printers to the public, including visiting the Cleveland public library to see how patrons interacted with the unit there.

Cleveland and D.C. are part of an expanding club of public libraries making 3-D printers available to patrons, often as part of a "maker lab" type environment. The Johnson County Public Library in the Kansas City suburbs debuted a "MakerSpace" in the spring with a MakerBot 3-D printer, iMacs, cameras and other equipment and software people might not normally be able to access at home.

The Westport Public Library in Connecticut launched a similar Maker Space with a 3-D printer in July of 2012 after a successful "Maker Faire" showcasing the tech in the spring before.  Ben Miller, director of the public library in Sauk City, Wis., called their acquisition of a 3-D printer in 2012 part of a larger move to "creation rather than consumption."

Correction: This story originally stated, incorrectly, that the Westport Public Library launched it's Maker Space this year instead of last year. We regret the error.