The Pros
If you imagine your life with a 3D printer at your disposal, you will likely come up with an endless list of things that you could do with it. There are simple, mundane applications, such as printing out tools or utensils that you might need around the house. Just think of a weekend project, like shelf-installation, and picture how much easier it would be to print out shelving or mounts at home. You could easily create jewelry that is one of a kind or produce quick toys for your kids or grandkids.
Once you think of humanitarian uses for 3D printing, you will see the way that such a product has the potential to really change our world. If, for instance, volunteers had access to this technology at refugee camps, they could print out cots, plates, or even medical supplies as they needed them. This would allow them access to supplies on an unlimited basis and spare them from trying to route shipments around hostile locations.
Education is another area that would benefit greatly from 3D printing technology. Art students could create sculptures from two-dimensional sketches and anatomy students could produce 3D models of the human body from textbooks. Think of how much easier it would be to understand physics or other abstract concepts if teachers could print out examples to illustrate important lessons.