lol, like a nerd I immediately noticed the cameo of Bubo, the mechanical replica of Athena's pet owl in the original clash of the titans movie, in the new Clash of the Titans movie.
Perseus: *digging in an armoury crate* "what's this?"
*mechanical owl flapping, eyes wigging out and making noise*
Soldier: "just leave it."
I think I only know one or two people other than myself, that would have also immediately noticed the cameo. :-P