I’m searching for a tool like Infinite scroll http://www.infinite-scroll.com/ to run on the client side and load data progressively in chunks, but a technology that will additionally allow progressive loading in both directions (up and down the page), and cleans up after itself when a certain threshold of data is met either above or below the current position. For example, it would clean up the head and/or tail when it gets so large or so far away from the current position.
Although the tool is intended for page content (up/down scrolling) I suppose it might be closer in concept to something like Google Maps in which multiple directions can be panned, infinitely.
Theoretically this would allow for a circular and infinite scrolling page when set in motion.
It sounds like Screw (scroll + view) will do what you’re looking for, except for maybe the automatic cleanup part.