Roll Fold your own giant paper robots! Many delightful designs, including the Whale-Copter(?), the Kanga-Bot, and a suprisingly familiar little guy. Hours of fun, at least until you pass out from blood loss following massive paper cuts. (Link courtesy Pixelsurgeon by way of Veer.)
Le Crimp (mostly en français) is a French collective that explores organic and abstract geometric [ I | II | III ] (PDFs) approaches to the art of origami. Read the white papers, browse the gallery or watch videos of artworks being made or being used in still-motion animations
Minimal origami is paper folding with just one fold. A single fold in a piece of paper is enough to make a swan or an interesting curve. Notably, Paul Jackson has made beautiful one crease origami structures.
Polyscene--Folded paper, and paper and wire, sculptures. There are more in the artist's Flickr stream.
Kokigami: origami for Mr. Happy. (Not, not this. And not ninjas, either.) The sensuous practise of Kokigami originated from the ancient Japanese art form of giving beautifully wrapped gifts.
Astonishing geometric art using only folded paper plates, from Bradford Hansen-Smith at wholemovement. View the gallery of fantastic polyhedral creations, and learn how to do it yourself. (For more fun with paper plates, see also Paper Plate Education: Serving the Universe on a Paper Plate.)