There are packing peanuts made of corn starch now, completely biodegradable. My physics teaher in high school used to give them to us to eat whenever he ordered new lab equipment. They taste sort of like cheese-less curly cheetos, if that makes any sense.
The fact that they're biodegradable is all well and good, but the novelty will wear off sooner or later. If they start to become more commonplace, I'll have to lump the idea in with Ethanol fuel in my list of stupid ideas. I mean, it's food, for chrissakes. It should be used as such. There are people starving all over the world, and we're using it to cushion items in shipping and fuel our cars?