CNN has an excellent article on Neil Gershenfeld, who is definitely on the list of Coolest Geek Ever. He's an MIT professor who teaches the course How To Make (Almost) Anything.
He also forsees a future where the printers attached to your computer can not only create newsletters and photos, but also three-dimensional objects like chairs and electronics.
Woah... so why isn't this a Half Baked idea? Well, because he's already damn close:
Want a new dining room chair? You'll design it on a PC and press PRINT, and your personal fabricator will create it for you right before your eyes. Just make sure tray No. 2 has enough wood.
The scaled-down model is a ways out, but factory-sized units are already available! He already has 15 around the world. He calls them Fab Labs. These are about $40,000 a pop, and come with laser cutters, sign cutters, milling machines, amongst others. All the pieces are tied together with open-source CAD/CAM software to help you design and make (almost) anything. You can make computers, robot cars, even small buildings.
Heck... given enough materials it might be possible for a Fab Lab to make little baby Fab Labs!
Naturally, there are issues with scale. A specialized factory will be able to make products more efficiently than a Fab Lab. However, those specialized factories require so much initial capital to create, and might be outdated in a year. Therefore, the generalistic Fab Lab might soon be the optimal choice. Soon we may never have factories again... just designers solving the latest problems!
I know what I want for Christmas...