There are an inordinate number of ways to mimic a leaf, as it turns out, as is beautifully illustrated below:
Photo credit: Josiah Townsend, available by Creative Commons License
Photo credit: Ryan G. Fessenden, available by Creative Commons License
Leaf mimic Photo credit: Sandilya Theuerkauf available by Creative Commons License
Leaf mimic katydid Photo credt: Geoff Gallice, Fotopedia available under a Creative Commons License
Work by Josiah Townsend, Ryan G. Fessenden, Geoff Gallice and Sandilya Theuerkauf; all licensed to share by Creative Commons.