Valerie Belmonte, a photographer, bumped into a book containing tactile images - that is to say, images with raised relief. Tactile images can be used by visually impaired folks to gain an understanding of visual material that would otherwise be difficult to do.
Valerie posts a list of links to research on tactile images and 3D printing, which obviously can be used to produce such 3D images. Most fascinating for us:
The possibilities for applying tactile images to the study of nearly any discipline are plentiful. There are groups experimenting with tactile mathematical models, architectural design, artworks, and even combined audio-tactile devices.