http://www.gizmag.com/wood-foam-insulation/31133/

Might not be news to all of you,
but it is the first time i read about it in this form.

Seems kind of promising in terms of base material used.
If it can be “foamed up” using co2 or other natural gases …

If it uses a low % of material VS air once it is foamed,
it could be very very cheap to supply
( as in using a mix of many wood industry residues )

Even greener if the natural wood “glue” is used in the biding process!!

Then, what about resistance to insects and fungus ??

I still prefer the inertness of “rock wool” though.