Our challenge is the desire from one of our production channels to always have PDFs centered in the specified media size. Easy enough to do if you want to open and alter each PDF needing this. But much more desirable to have--as nearly as possible--a drop applet way of doing this. Basically, where trim and media box are not the same, it would mean taking absolute values for dimensions of trim box, setting media box to have origins of 0, 0 and dimensions of |trim box size| + 144 pts (2 inches). Then, in turn, altering trim box to have origin of 72, 72 and same original dimensions. (Of course, the still stickier problem is that trim box is often not correctly set in the first place. But I've got to eat this elephant one bite at a time, so....)