gistfile1.js

// Add to global namespace

$(document).ready(function(){
    
   window.coolfunc = function(arg){
       alert(arg);
   }
   
   coolfunc('Hi!');
   
});

coolfunc('oh hi too!');

// Declare your own name space with object (http://stackoverflow.com/a/3402906/662826)

$(document).ready(function(){
    // Example from SO shows var MyApp, but this doesn't make the var global, 
    // so for use within .ready() we must omit 'var'
    MyApp = { 
        showMessage:   function(arg){
           alert(arg);
        }
    };
   
   MyApp.showMessage('hi');
   
});

MyApp.showMessage('hello');

// Closures? (from link above)

// Self invoke? (http://stackoverflow.com/a/17567235/662826)