jquery.getscript.multi.js

(function( jQuery ) {

	var getScript = jQuery.getScript;

	jQuery.getScript = function( resources, callback ) {

		var // reference declaration & localization
		length = resources.length, 
		handler = function() { counter++; },
		deferreds = [],
		counter = 0, 
		idx = 0;

		for ( ; idx < length; idx++ ) {
			deferreds.push(
				getScript( resources[ idx ], handler )
			);
		}

		jQuery.when.apply( null, deferreds ).then(function() {
			callback && callback();
		});
	};

})( jQuery );

var deps = [ "http://documentcloud.github.com/backbone/backbone-min.js", 
             "http://documentcloud.github.com/underscore/underscore-min.js" ];


jQuery.getScript( deps, function( jqXhr ) {
	console.log( jqXhr );
	console.log( [ _, Backbone ] );
});