Always good to use up what you have in your cupboards.
Although the Rice Krispie recipe calls for a full bag of marshmallows, I had half, so I just cut the recipe in half and made a smaller pan.
With this recipe as well you can use any types of cereal- I've done that before. You can also add in bits of nuts, chipits, dried fruit, etc..
I like going through the cupboards every so often and using up what I have in them, especially items in the fridge, which don't last quite as long.
A great site to check YOUR cupboard/fridge ingrediants against is Big Oven.