i don't know if this would work with a slideshow program- but you can make hidden journaling

.
http://home.mchsi.com/~mydnyghtwhyspers/anihidden.gif
this is what i did really quick, using photoshop and adobe image ready.
a really simply animation, just the hidden journaling open and closed, but you could make it as complicated as you wanted, i guess. what i did was...
created the 'closed' file first in photoshop. and then saved it. then i made the 'open' file second and saved it. i animated the frames in adobe image ready.