Over the past few years, the technology of 3D printing has shown itself to be a complete game changer. In a few very short years, with the initial investment of a printer, it will be possible to download physical objects. The plastic molding industry is going to be the first to feel the pain but eventually all manufacturing will be at risk. I expect to be a grandfather before complex electronics can be printed at home, but a wide variety of knickknacks and general household replacement items will be coming sooner, e.g. already you can download and print replacement knobs for a variety of items. One aspect of this revolution will be that designs of objects are going to go the way of entertainment content. File sharing piracy is going to drive the price down considerably. If you ask too high a price for your design, it will push people over the ethical boundary towards piracy. We will also see the crowd power that has guided the open source software community begin to incrementally improve our daily household objects and drive prices down even further.
An advantage that I had not foreseen about the Mac App Store is how easy it is to switch computers. My operating system and program settings are backed up to iCloud, my music is in iTunes Match, and the App Store knows all the apps I've bought and allows me to download them whenever I want. So I log into a brand new computer, and within minutes (okay, hours), I've got all my apps installed and configured just how I like them. Back when I was a Windows user, I used to have to format and reinstall the OS and all my apps – from physical media, children! – and then remember how I had it all configured. My daughter will never know what a huge time saver the App Store is.
Now, imagine that App Store magic applies to Stuff. Say I want to move to another spot on the globe. I can just take all my crap down to the local materials recycling place, dump it in, and when I get to my new home, I simply re-download and print it all! Wow!
How will the 3D printing revolution change how our governments can legislate us?
In the very near future, it will be impossible to effectively enforce bans on any type of non-organic object. (I would argue that bans on organic substances are already shown to be ineffective.) We're about to finish up 2012, a year that started with the near-fatal shooting of a US congresswoman in Arizona, and ended with the massacre of twenty innocent kindergarteners in Connecticut, with plenty of similar events in between. Historically, I have tended to side politically with those demanding stricter gun laws, but I fully acknowledge that the issue is [extremely
gray](/2008/10/16/everything-is-gray/). You can probably see where I'm going with this. In the very near future, it's not really going to matter. You can already search the internet for "3d printer gun" or "wikiweapon" and download the file for a 3D printer to print up the pieces to a working semi-automatic rifle. It doesn't work for very many rounds, but that's a technical matter of printing with stronger materials that will be solved very soon.
While gun legislation has worked in the past in other countries to decrease gun violence, by removing guns from the culture, I think it's already too late to change the gun culture in the United States via legislative fiat. In much the same way that the printing press made dispersal of information impossible for governments to contain, 3D printing is poised to change how we, both as citizens and rulers, look at our physical possessions.