Here is my most favorite Hidden Mickey. It was in a mural next to Body Wars in Wonders of Life at EPCOT.
Tim, I took this several years ago and had to actually confirm where it was with Steve Barrett. I submitted it to Steve's web site after I heard it was his favorite and he had no pic of it. Here is the way he explains the location on his web site. "In the mural above the entrance to Body Wars is a small side view of Mickey Mouse, who is gazing toward the upper left of the mural. He's in the right-most green "broccoli-like" tissue, just above a blue "vein"."