JavaScript namespacing (depends on jQuery)

namespace.js

(function (global, $) {
  global.namespace = function (nsName, obj) {
    var level, names, name;
    level = global;
    names = nsName.split('.');
    while(name = names.shift()) {
      level[name] = level[name] || {};
      level = level[name];
    }
    $.extend(level, obj);
  }
})(this, jQuery);

// Usage:
namespace('one.two.three', {
  four: (function () {})
});