That does work, my musically talented mate (the one who did my Zombies Now theme tune) used to do it to copyright his work, but now he has some money he uses www.copyright.com. But Circy's way definately is a known way for poor people like us to copyright our work.
That link is down..or something, I can't read the language its written in.
You should check out the copyright act laws in your country. I've known for a while now that Australia has an internet Copyright law that states your work is copyright to you as soon as it is uploaded.
i usually include some kind of message in the readme letting the player know they've been ripped off if they have bought the game. Of course it only works if they read it.
it might make them think twice before bying a compilation with 100's of games on.