Spiral Pen

This pen would be in the shape of a single helix that twists wider and wider according to the golden mean ratio. So you know how the joints in your fingers and then your hand and then your forearm are all in golden mean ratio to eachother, so this pen (or paint brush handle or pistol handle etc.) would spiral around your hand and wrist. My prototype flexible wire fits the hand quite nicely with three twists, one around the tip of the index finger, one around the base of that finger and the last going under the thumb and around the wrist. The wire could be a pen itself, or it could be a grip with a straight pen attached. It could be for people who don't have the use of their thumbs or just for extra precision.