It's not uncommon to forget about frozen items in the back of your freezer, especially if you also have a chest freezer. Bento weblog Lunch in a Box has a great method of remembering what lurks in your freezer — cover advertising magnets with food photos from supermarket catalogues so you can see what's inside by checking the magnets.
Most of us get loads of magnets from restaurants with home delivery, lawyers, hair salons and all other manner of businesses. Save up several of these and cut out photos of foods you usually buy from grocery store flyers. When you pull out the food to cook move the magnet to another side of the freezer.
Magnets to track freezer inventory [Lunch in a Box]