http://chem.sci.utsunomiya-u.ac.jp/v7n1/nagao/
modelling the structure by means of up-to-date 3 dimensional molding method offers an effective teaching aid.
(Freely “rearranged” from the babelfish translation of the page above.)
I highly recommend that you take a look at this article even if you don’t know japanese, since its pictures (scroll down a bit) beautifully illustrate several techniques currently used to make real objects from 3D models. In this case the subjects are molecular structures: these techniques not only bring them to a human scale but also to the human world, thus helping scientists twice. Furthermore, some of the machines used, like the Roland mdx scanner and milling machine, are getting cheap and easy to use enough that in a near future they may become as common as photocopiers!