Surplus Continuous Scrolling in AS3 / Flex

What is the logic that goes behind making a surplus continuous scrolling using a vScroller in Flex or vScrollbar/scrollpane in AS 3.0.

[LEFT]The question that i really have here is, suppose if the content is a very big in its height - that is if the scrollcontent has around 200-300 loader/sprites/movieclips to be scrolled one after the other vertically, what ever may be the case only 3-4 sprites will be shown in the display area of the scroller. [/LEFT]

In this scenario
[LIST=1]
[]How do we manage the rest of the displayobjects within the scroller ?
[
]How to maintain a good scroll speed while the 300 display objects are being scrolled ?
[*]Can we just have only 4 placeholders and loop the 300 display objects between the 4 placeholders ?
[/LIST]Any Ideas…