Simple example courtesy of Steven Robinson. You can just return a seperate object containing public mehods, but this way is better as then all functions are accessible within the outer function

gistfile1.txt

<script type="text/javascript">

var COUNTER = (function () {

  var counter = {},

		num = 0,

		increment = function () {
			console.log(num += 1);
		},

		reset = function () {
			num = 0;
		};

	counter.inc   = increment;
	counter.reset = reset;

	return counter;

}());

COUNTER.inc();
COUNTER.inc();
COUNTER.inc();
COUNTER.reset();
COUNTER.inc();
COUNTER.inc();
COUNTER.inc();

</script>