Have you ever looked at a simple fanned piece of computer paper? This is the basic accordian binding. You can make your folds wider to accomodate photos, or fold it long ways and then accordian the sheet to create pockets, even trim the pockets to create different shapes. But what else can a fan folded sheet become?
I have been thinking about the angle at which you fold the paper - really neat things happen when you do this. The folded sheet winds around, or if you reverse half the mountain folds to valley folds you get interesting structures.