For small mobile devices especially (but probably applies to iphone and even desktops maybe):
If you are trying to read a news article on (say) Opera-Mini (A fine browser by any standard) it is annoying and distracting when scrolling to the next page: I invariably have to re-scan the text to regain my place...
Different apps seem to do this 'jump-scrolling' differently: some scroll the last line OFF the screen, some seem to move only partially up the page: but both systems can mean you get lost.
When I propose is that the last line (this is the assumption: you only scroll when you have finished reading the last line): is highlighted and flash briefly as it scrolls.
I would imagine (this is the half-bakery of course...no testing on this at all... ;-) ) that your eye would instinctively track the highlighted-line and therefore line-up with the next bit of text correctly....allowing you to scroll much quicker and never lose your place...-- monojohnny, Feb 26 2009random, halfbakery