Fridgeezoo gives a voice to all the critters of the icebox by howling and screaming if the refrigerator door gets held open too long. The gadgets are shaped like little milk cartons dressed up as various cold-climate creatures such as a polar bear, a penguin, a seal or a walrus. Of course, since these Japanese gadgets are probably light-activated, you can save even more energy just by unscrewing the refrigerator light.
(Via Oh Gizmo! and Craziest Gadgets)