L Spiral
This is a generalization of a diagram I sae from d3lt4 on Tumblr:
http://www.d3lt4.com/post/97892342214/fiboncci-sequence-square-art-print-leonardo
It is constructed by rotating and dilating the L shape to fit in with itself, rotated 90 degrees. There are some interesting properties that develop based on the height/width ratio and the thickness of the L-shape. D3lt4's diagram is based on an L from a square with thickness half of the width.