(function($) {
    $.fn.lavaLamp = function(o) {
        o = $.extend({ fx: "linear", speed: 500, click: function() { } }, o || {});

        return this.each(function() {
            var me = $(this), noop = function() { },
            $back = $('<li class="back"><div class="left"></div></li>').appendTo(me),
            $li = $("li", this), curr = $("li.current", this)[0] || $($li[0]).addClass("current")[0];

            $li.not(".back").hover(function() {
                move(this);
            }, noop);

            $(this).hover(noop, function() {
                move(curr);
            });

            $li.click(function(e) {
                setCurr(this);
                return o.click.apply(this, [e, this]);
            });

            setCurr(curr);

            function setCurr(el) {
                $back.css({ "left": el.offsetLeft + "px", "width": el.offsetWidth + "px" });
                curr = el;
            };

            function move(el) {
                $back.each(function() {
                    $(this).dequeue();
                }
            ).animate({
                width: el.offsetWidth,
                left: el.offsetLeft
            }, o.speed, o.fx);
            };

        });
    };
})(jQuery);