I like this idea especially for spells. I just assembled a spell book for my daughter into power point, created a colored cover and back and printed it out and she bound it up. these were her spells from the many she could choose from.
actually, I think you could go to ways with this: (1) spell cards, which you then select your "deck" as your "book", or
(2) Have a program that generates your spell book through a Q&A, and then you hit print and it prints it all out so that it can be folded and bound.
for combat, i think its less useful on a standard game and i would rather have a pc based monster generator or monster book to work with as a GM.
I could see cards being more useful for initiative. I am almost certainly going to go there for that as they serve as handy markers to see who goes when.