Simplest/Cleanest way to implement singleton in JavaScript?

Question

What is the simplest/cleanest way to implement singleton pattern in JavaScript?

Answer 1

Isn't this a singleton too?

function Singleton() {
    var i = 0;
    var self = this;

    this.doStuff = function () {
        i = i + 1;
        console.log( 'do stuff',i );
    };

    Singleton = function () { return self };
    return this;
}

s = Singleton();
s.doStuff();