My father's ex-girlfriend, Dee, used to make this AMAZING dessert out of - seriously - nothing but pudding and graham crackers. The other day I actually had a craving for it, and emailed my father to see if he knew how to make it. This was his reply:
"Dee bought a large box of chocolate pudding mix and made the pudding in the microwave. she simply put a layer of graham crackers down on the bottom of an 8 x 8 inch pan, preferably glass, then a layer of pudding, then crackers, pudding, etc. until all the pudding was used up. I think she always made sure that the top layer was graham crackers because pudding tends to get hard when left exposed. Whipped cream on top makes it a perfect Summer dessert."
I think he was mistaken about the final layer - I think it was pudding, and she used to just lay plastic wrap across the top, to keep the "skin" from forming. The key to this dessert is to refrigerate it for a few hours before serving; the moisture from the pudding softens the graham crackers and makes them almost cake-like. (Also, make the pudding layers no more than twice as thick as the crackers... you want lots of layers!)
I remember Dee saying she'd also made it with vanilla pudding and cinnamon graham crackers. I've never tried it that way, but I can vouch for the chocolate version - it's REALLY good!