It is well known that I am a optimist about technology. I believe strongly in the power of technology as a tool, it is not a solution in itself. Technology will not save the world, but it helps people and gives people power that they may not have had before. Example: Any person with an idea and a moderate income can get the equipment and make music, a movie or a documentary on their own. In the past this could only be done the rich and the powerful. Technology enables the smallest of us to do what was once done by the privileged.
The first time I heard about 3d printing I was very young. I believe it was GM using 3d printing to prototype parts for their automobiles. They would have a vat of goo and would cross lasers into the goo. Similar to cancer radiation therapy the lasers would intersect and at the point of intersection the resin would harden. After hours and hours of creating these individual hardened points they would form into an object that could be extracted from the vat, cleaned up and used for prototyping.
Skip forward 20 years or so and you can purchase (or make your own) 3d printer for under $600. You connect the printer to a computer, use a spool of what amounts to colored plastic thread as construction material. Create a model of your own design or download something from Thingverse or a similar site and after a bit you can hold something real in your hand. This thing you are holding once only existed on the internet or in your imagination and now it has entered the real world.
The possibilities here are staggering. Any human with a decent idea and a little bit of know how can create something. Just like ameteur music and video creators there is bound to be a lot of junk, but once you sift through it there is sure to be some gems. After the hype wears off the potential is that a new manufacturing sector is created one that is based on the individual rather than large corporations. Large scale manufacturing will still need to exist, but greater opportunities open up for the inventors and creators among us.
This is just an introduction, so I am not going to dive into some of the intellectual property implications (Coupled with 3d scanners I can basically print anything) or some of the scare tactics people are using like printing a gun. There are a host of startups entering into the space and this era has already begun. Jump over to Facebook if you want to discuss it more.