oooh.. spring loaded flash finger!! tons oh fun.
I never use flash paper much. Played with it for a bit long ago, but I'm sure others will chime in with ideas.
I would say, I guess, if you do some sort of "pan" routine.. it would be good for that.
Plenty of other things you can use it for though.
How big of pads do you have? Do any mentalism magic? Can always use a pencil for predicitions and write them (or pretend to) on the flash paper, then light it up.