If you're into origami and/or the alphabet, you'll love this template that shows you how to fold 3D letters of the alphabet out of paper. It appears to be part of a computational puzzle series designed at MIT.
The crease pattern by itself provides a kind of encoding of a maze, which can be decoded by folding. We applied this idea to encode textual messages in crease patterns that can be decoded by folding. Figure 1 shows a simple font we designed with the constraint that each character is a small orthogonal maze…. (With larger dimensions, the font might be easier to read, but harder to fold.)