Douglas Crockford's Supplant (http://javascript.crockford.com/remedial.html)

supplant.js

// Douglas Crockford's Supplant
if(!String.prototype.supplant){
	String.prototype.supplant = function(o){
		return this.replace(/\{([^{}]*)\}/g, function(a, b){
			var r = o[b];
			return typeof r === 'string' || typeof r === 'number' ? r : a;
		});
	};
}