The Nokia Lumia 820 smartphone has a replaceable backplate. This allows 820 owners to buy new covers from Nokia with different colors and features like shock protection. That's not all you can do with it, though. Nokia is going the extra mile for their geekier fans, and providing templates for people to design their own custom shells. 3D printing is fantastic, and it will certainly play an important role in manufacturing going forward. That said, its real world use has been oversold by many of us in the tech field.