Here's something we've been eating since jr high and I don't remember exactly where it came from. It's not low cal, but that doesn't mean that it's not nutritious. Plus, it's quick and easy. I remember eating it often after school and the protein in the peanut butter in a few of these plus a glass of milk would help hold me over until dinner. I still like to snack on these and my kids love them too, especially if I let them make faces with their toppings. I prefer them crammed with as many toppings as will stick to the peanut butter.
For every half graham cracker, spread about 1 tablespoon (more or less) of peanut butter. Sprinkle or arrange a couple teaspoons of toppings as desired. You can also add mini marshmallows, but I prefer them without.