How do you create a "limited fixed div"?
qhoxie: I did this in jQuery at one time.  Hopefully this is helpful.  $(window).scroll(function() {
    var offsetTop = $(window).scrollTop();
    $("#target").css({top: offsetTop});
  });

To explain, whenever the viewport is scrolled, the offset of the viewport to the top of the page is set (offsetTop).  Then the #target element is moved to follow the viewport.  That will give a fixed effect, so what you need to do is set the max offsetTop to (max depth - #target height).Note:  Dimension type calculations vary widely among browsers, so using a library like jQuery dimensions is quite helpful.