Something gives me the feeling that no one got the punchline of 'J0HN'.

Here It Goes:
J0HN was ripping off those dumb flash submissions that have opening sequences that go longer than the movie itself.(Or at least feel that way).

In J0HN the opening sequence goes on for approximately 33 seconds, and it keeps asking you if you are ready for john. Then the actual movie itself is only a badly constructed picture of J0HN's face for 2 seconds.
That is then followed by a text that reads 'Cool wasn't it. THE END'.

So that is the meaning of J0HN