Hijack console.log, console.warn, and console.error without breaking the default browser function.

Console.log() override.js

var cl,ce,cw;

if(window.console && console.log){
	cl = console.log;
	console.log = function(){
		MyLogFunction(arguments);
		cl.apply(this, arguments)
	}
}

if(window.console && console.warn){
	cw = console.warn;
	console.warn = function(){
		MyWarnFunction(arguments);
		cw.apply(this, arguments)
	}
}

if(window.console && console.error){
	ce = console.error;
	console.error = function(){
	MyErrorFunction(arguments);
		ce.apply(this, arguments)
	}
}

The massageArguments method will get passed the arguments object and from there you can apply your formatting to each of the arguments that were originally passed to the console.<method>()