I too was interested in this last year. However I'm yet to be convinced.

The opposition don't agree.... see..

http://www.celotex.co.uk/pdf/Multi-foil_Bulletin.pdf

In response to this the company in question had some independent testing
done. Last December I asked them for details of how the test were done. They
sent me ...

http://makeashorterlink.com/?K6DA127EA

and

http://makeashorterlink.com/?R6EA537EA

However these do not describe the test in detail or how it's performed...

When I pressed them for details they said....

"Sorry, no, these are not for public release"

I have no idea if there have been any further developments dince Dec 04....

Roy