We firmly believe that everything should be 3D printable. That is, if you're in the market for some sort of new widget or piece of furniture or you just need to fix something, you should be able to order up a schematic and print it out in your living room. And if you're in the market for a new airplane, you should be able to do the same thing.
MakerPlane is a project to create an open source airplane, most of the parts for which can be created on a 3D printer or with a CNC mill. You may not have a 3D printer or a CNC mill at home, but your local makerspace likely will (and you probably have a local makerspace unless you live somewhere really, really boring). This is not to say that building your own airplane will suddenly become easy; it'll still be a lot of work, but it'll be a lot less work than it would be otherwise.
The MakerPlane will be a single engine, high wing, two-seat light sport aircraft, meaning that with just 20 hours of instruction and after passing some tests, you'll be able to fly this thing all by yourself. It's still in the development stage, but a prototype should by flying by 2014. If you want to build your own at that point, accessing the plans won't cost you a jot. The materials won't be free, and there will certainly be a substantial number of parts that you'll have to buy anyway, but even the normally very expensive stuff (like instrumentation) should be doable with things like open source software running on iPads.
Part of what's so great about this design is that it'll allow for modifications and improvements. Want low wings instead of high wings? Slap 'em on. Different power plant? No problem. Ballistic parachute? Hey, it already comes with one! Sweet! The Maker movement is all about synthesizing crowdsourced expertise, and we're about at the point where we can combine that with computerized construction techniques to really begin to make everything by ourselves. Even airplanes.