Discovery Channel gives us a view into what could potential replace our current types of "pink" home insulation: mushrooms.
Mushroom spores, actually.
Although excellent insulators, traditional polystyrene and polyurethane foam blends are made from petroleum, are expensive to produce, and are not biodegradable.
The patented Greensulate formula is an organic, fire-retardant board made of water, flour, minerals and mushroom spores. It not only hinders heat flow but could also be modified to produce sustainable, "growable" homes.It's been developed by a couple of kids from Rensselaer Polytechnic Institute in Troy, N.Y. They claim that these spores grow very quickly, couple of weeks, and that the end product will be quite cheap to produce. They're creating the company to market this...as we speak.
Another article on the topic here.