You can build your own home 3d printer now from a kite from
Maker Bot
Determined folk can build them for around 1/3rd of the price if they do a bit of searching for the bearings and rodding themselves.
Googling for open source 3D printing will give geeks many pleasurable fantasies - I am at the threshold of making a purchase and will still be there for the next few years until I can persuade myself that it would be a wise purchase.
The UK product is known as
Reprap and was created in the University of Bath.
I have a 3d printed ball within a cage that was printed at a demonstration of rapid prototyping at Leeds University in 1992 or thereabouts.