It might be one of the most notorious of all the Easter Eggs in Batman films but the Joker playing card at the end of Batman Begins is still one of the best. It is of course a replica of the Joker Card from Grant Morrison's "Arkham Asylum" comic, which in itself was a nice Egg, but the best part is the evidence label that carries the name J. Kerr - in turn one of the Joker's favourite comic book aliases (Joe Kerr). The greatest inference is of course that Joker was able to infiltrate the police department at will, and that's all he did, playing the long game. Nolan threw in a trick in The Dark Knight when he playfully suggested that Mr Reese was set to become The Riddler - given the similar sound to "mysteries" - but it was no more than a joke. And it's hard to resist the feeling that it was a little stab at the silliness of Mr E. Nigma.
