In the early 80's, "moonwalk" was also a breakdancing move whereby the dancer would walk backwards while sliding his feet along the ground. The overall effect was such that the dancer's body looked like it had a natural walking motion, but he'd be going in the wrong direction. Michael Jackson was a frequent practitioner.
I remember trying to moonwalk in front of a full-length mirror when I was a kid, only to come to the horrible realization that I'm a terrible dancer. Not that that stops me :)