I really like this simple analogy that I stumbled across on a blog. I reblogged the whole thing on my blog at printedsolid.com "Imagine a world where we can look at an object, and go, “I want that.” Ctrl+C, Ctrl+V, wait for a few minutes… congratulations, you now have your own copy. Sounds like science fiction? Nope! The technology to do that is already here! Sure, it is rough around the edges (ability to replicate fine detail), and sure, it only works on exterior surfaces."