Wandering off topic, but I have been daydreaming about an app that lets you create "delta files" of changes to PDFs for different game systems...not just monster stats but also how things like traps or social encounters are handled...and then integrates those into the PDF, either actually changing the content of the PDF dynamically (which gets tricky because different systems will take up more/less room) or maybe something like displaying the PDF in a browser and using a pop-up.
You could then share the delta file with other people and, if they own the original PDF, they can use it to do the conversions.
Does that make sense? I don't mind doing the conversions, but:
a) I don't want to do them on the fly
b) I don't want to have to refer back and forth between the adventure and my notes
c) We shouldn't each have to repeat all the work!
Or, put another way: it would be great if the gaming industry (minus WotC?) could agree on a standard format for doing this. The current state reminds me of every electronics manufacturer having their own proprietary charging cables. (Or...wait for it...toner cartriges.)