3D origami

My question still remains: how to generalize origami-like techniques to 3D objects...
so that one can start with a (simple enough) 3D object and get (simple and usable) instructions to recreate it (with some degree of approximation)?

Here are some nice things that go in the direction of an answer...

A great collection of images on flickr: here.

A video: here.

And a nice general technique to create 3D shapes by "rotation": here (paper).