Styrofoam might great for all your packing needs, but the chemicals and processes needed to make it aren't exactly environmentally-friendly.  As a solution to this, the researchers at the Fraunhofer Institute have successfully created an alternative made from actual wood.

The wood is first finely grounded into a slimy goop which then gets frothed. And unlike conventional insulating sprays, the natural materials in the wood will harden all by itself after it's been sprayed onto a surface.

The wood foam can also be produced in sheets just like the large panels of expandable polystyrene you can find at home building stores. While this particular process does require additional chemicals to help the foam rise and set, but the final product is still more sustainable and environmentally-friendly than petrochemical alternatives.

[Fraunhofer]