Wool insulation?

A couple of people responded suggesting sheep's wool insulation. I had looked into this briefly a while back, but dropped it early on because I thought it would be too expensive. I took another look at a company called Oregon Shepherd, in Portland Oregon. It seems like wool will actually be cheaper than using EPS, will not settle and will still be extremely light. This website also claims that the wool will resist mold and mildew. Oregon Shepherd claims around R-4 per inch, which is slightly better than cellulose, and not far behind EPS. Sounds good to me. My one complaint is that there is not very much technical information on their website. I will call them tomorrow with some more questions though.