What in the world is a wonder box? I asked the same question when it was announced we would be making them for a church activity. Okay, I'm always up for making adventurous new things. I just didn't realize how wonderful and useful the wonder box would be! I even ended up making 2 more for my sisters-in-law for Christmas. There is some great information and instructions here. Which is also where I got the pics (I'm feeling too lazy to go take pics of my own.)
You just have to heat whatever you're cooking through, then you can turn off the heat and stick it in the box. It will stay hot and continue cooking your food! Like I said, wonder-ful! The things I use it for most often are yogurt (a post about this coming soon) and rice. It can also be used to keep food cold-- like if you want to take ice cream to a picnic!
Pros: Decrease the amount of energy you use in cooking. Versatile, easy to make
Cons: Bulky to store, and the food you cook pretty much must be in liquid form. (So although I've heard there is a way you can bake bread in it, not sure how that would work.)