How can I declare a global require in NodeJS?

Possible Duplicate:
node.js global variables?

How can i include a file or a script in node js, that i can access it global. I would like to extend the standard Array Object with some functions, but i dont like to do this in app.js and wenn i declare it in a module, it is not possible to access it global.

Is there a possibility with a other command to do this?