What is it about cameos we love so much? The surprise factor? The chance to see actors and real people sending up their set-in-stone images? Or just the hilarious disconnect we get when someone as famous as, say, Harrison Ford, strolls into a film that's clearly not ever going to show up on his official resume? How about all of the above?

We tried to keep some of these plot twists intact for you here, but if you don't want to know which mellow musician went blue in 'Funny People,' which unlikely 'Saturday Night Live' alum popped up in between Nazi bloodbaths -- or which comedy legend made this year's most-talked-about (and best kept secret) cameo -- then for the love of Mike Tyson, don't read any further!