A host explains various objects created from molten plastic and a MakerBot 3-D printer at the 2013 CeBIT technology trade fair.

In his State of the Union address earlier this year, President Obama argued that 3-D printing could "revolutionize the way we make almost everything." His speech echoed a sentiment that has been gaining traction among entrepreneurs and techies for some time now.

Three-dimensional printing, also known as additive manufacturing, has been around since the late 1980s and has produced some exciting advances. Companies in the industry have printed aerospace parts, industrial manufacturing equipment, and even human stem cells. One company is working on a technique to print functioning human organs. Although all of this is promising, 3-D printing technology still has a long way to go.