I found this great article about insulation on the Energy Boomer blog.

A broad array of new insulation types are in development. They hold the promise of offering values as high as R-20 or more.

One idea being researched is gas-filled panels. They use pockets of a low-conductivity gas such as argon, krypton or xenon.

Researchers are testing vacuum insulation panels. They rely on a vacuum between two layers of metal to create very high R-values. These work like a thermos bottle.

Aerogels are low-density fibers of silica or other materials. They can offer R-values as high as R-35 per inch.

Click Here to read the entire article.