[Piwoslaw]

There was an article in Home Power magazine many years ago (late '90's?) about insulating the fridge and building a cabinet arount it. IIRC it was good for a 5%-10% energy reduction.

I can understand not wanting bare, toxic insulation in the kitchen, but what about cork? I read that it's a good insulator, has a nice look, and you can use thumbtacks, as BicycleBob suggested. Just remember that metal thumbtacks are like little heat bridges...

The door can also have a piece of insulation glued to it, but make sure you have enough clearance to open it. I wonder how much heat is lost (gained) through the magnetic skirt around the door's perimeter, and how one would go about improving on that.

If you insulate the back of the fridge, then remember to leave room for free airflow from the compressor.

If there is enough space between the bottom of the fridge and the condenser/compressor you can add insulation there. Maybe a 5mm piece of styrofoam with aluminum foil on one side? Or just alu foil if there isn't enough room.

I've read about keeping large empty containers in the refrigerator to reduce the volume of air that escapes each time the door is opened. If they are filled with water, then the increased thermal mass helps keep the temperature low during a power outage.