I know the standard thing is to present scripts on A4 double-spaced etc, but I've just printed my 46 page script out with four pages to a piece of A4 (1,2 then flip over for 3,4) and it feels so light at 12 pages.
This is just for editing purposes so I can take it with me, but I wonder with people trying to save paper now ("Do you want a cash receipt, seeing it on screen will save paper) and producers sighing at the prospect of another 40 odd page script to read whether this will become in vogue.