I did a little googling about bubble-wrapping windows as cheap insulation, then took a roll that had been in the basement and started in. People are right: it's easy and effective, so long as you don't mind the effect. I used a foot-wide roll of the small bubbles. I didn't do the windows with my favorite views, and in a couple of cases, I only did the bottom three-fourths. The house seems much cozier now.