Slinky is lightweight, responsive and mobile-like navigation menu plugin. If you use iPod before, it behaves quite similar to it. Clicking on the parent menu it would slide to the left and reveal its children menu. You can go back to parent menu via top left back button.
There isn't a lot of options to configure. you can change the back button label, toggle the title display, animation speed and turn on/off for matching menu height. From the look of it, It supports infinite level of menu too.