They do excel spread sheets of invisibles too - guess the movie stuff, very well done.
I've since foud a ken and barbie guess the movie too. there are two characters in shot and the flesh has been replaced with ken and barbie - excellent. there's even one replaced by muppets.
I think I might start a thread with those too - they are very good.
A while ago we found an invisible quiz bound up into an executable. when you got the film title correct it put the flesh back in. On one particular film you could just about tell it was two seperate shots that had been merged. one with the character off screen and one with the character on. They then merged them and digitally edited out the character using the previous frame as a reference point.