Lego gets it, you get it
Chris Anderson has a couple of posts about a Lego product line called Factory; you download the software, you design your whatever-it-is, then you order the bricks. No more buying more bricks than you need; you get exactly what you want. Apparently that was a bit of logistics problem for Lego at first, but they have now found a way to fulfill your order, your whole order and nothing but your order.
(Oh, by the way, the installer is evil. First you must agree that you cannot use the things you design with the software commercially, then the software sends data about your computer to the Lego death camps. Or something like that.)