I'm trying to find a scriptaculous script (or create one) which keeps a vertical navigation bar "sticky" inside my viewport. While this may not be black magic (one could use the position:fixed css) there is a problem with this approach: If the navigation bar is longer than the viewport height the visitor won't be able to ever see the whole navigation. So I want that the navigation bar to not leave the viewport at its top but neither leave the parent container at its bottom. It should follow scroll events instantly without fancy/bouncing animations.
Is that possible? Google revealed nothing useful to me. You may know this kind of effect from slashdot's article comment navigator or google video's player box.
Update: Essentially that would be a rewrite of the jQuery plugin scrollFollow. It would be no problem if it lacked animations as I won't use them. But it should be able to stay within a defined parent container without clipping. The cookie handling is neither needed.