I came across this product when I was looking for cheap ways to decrease the heat inside our house.

I was surpised to find that this is available locally under "Flexseal Insulating paint". The paint is mixed with ceramic beads to give it insulating properties.

I really don't know if it is effective though, and how it would compare to insulating mats/foams/foil.

I saw it in Wilcon and it sells for 750/gallon. Not bad if it is effective.

Here's the website:
http://www.campbridge.com/p_cera.html