Here is a box I cut out using my new Silhouette. I downloaded the file from the Silhouette website for only 75 cents. I cut the base to fit a 12 x 12 page and then the top was small enough to fit on a smaller standard size paper. It was easy to put together and I am rather impressed with the results.
The best part is that the box is pretty big. 5 1/2 inches wide (from side to side, not point to point) and 3 inches tall. I think I am going to put some clear acetate inside to seal off the box before I use it.