I really like this:

In addition, Bryan Cranston went to ComiCon wearing a Walter White mask, didn't peel it off until he got to his panel. Nobody noticed him.

Also, I love that bit (in Superman 2?) when Clark Kent is about to tell Lois that he is Superman... His bearing changes completely, showing how much the way someone is standing up can alter our perception of them.

Oh, yeah - that was Chris Reeves's magic:

Superman Disguise

Brandon Routh's Clark was almost eerie - he nailed Chris Reeves's mannerisms perfectly (although I can't find a clip from the movie):

Brandon Routh audition 'Superman Returns' Behind The...