typeOf.js

(function($){

	var toString = Object.prototype.toString;
	
	var class2type = {
		"[object Boolean]": "boolean",
		"[object Number]": "number",
		"[object String]": "string",
		"[object Function]": "function",
		"[object Array]": "array",
		"[object Date]": "date",
		"[object RegExp]": "regexp"
	};

	$.typeOf = function( obj ) {
		if ( !obj ) {
			return obj === null ? "null" : typeof obj;
		}
		
		return class2type[ toString.call( obj ) ] || "object";
	};
	
})(jQuery || window);