CrystalMaker by Dr David Palmer of The Open University is an excellent program for exploring crystal structures, and creating your own crystal models is an extremely instructive way to learn about the structures of solids. If you have the full version of the program you will be able to save your own structures and QuickTime movies or Virtual Reality scenes. So why not buy or get your computer provider to buy the full version (details with the Demonstration copy) and be able to save your work for posterity!
The Demonstration Version of CrystalMaker can be downloaded from the CrystalMaker site,
http://www.crystalmaker.co.uk/crystalmaker/cm_demo.html
or from the Imperial College UK Info-Mac ftp site,
ftp://src.doc.ic.ac.uk/packages/mac-sumex/_Science_&_Math/crystal-maker-20-demo.hqx.