Have you ever heard of polyglots? This is so crazy. A polyglot is a program which can be interpreted as many programming languages. You don't believe me that something crazy like that is possible? Here is an example I've made: public gist
You can download the file at martin-thoma.com/python/polyglot.py.
I used three languages in this piece of code: Python, Brainfuck and Whitespace. You can try it with ideone.com. But please, copy the whole code!
It might be considered as cheating to use comments as often as I did and using two esoteric programming languages. Whitespace works only with whitespaces (space, tab) and Brainfuck needs only +-.;<>[]. Everything else is interpreted as a comment.
When I have much more freetime and I don't know what to do, I'll probably write some code with a more interesting output and which is not that obvious.