backpack?

I am making a graduation cake and the mom has requested that some of the girls' favorite things - bikinis, flip flops, car keys, etc - be incorporated into the cake. I want to make a backpack with the stuff falling out of it and I am having trouble envisioning how to achieve that effect. Trying to figure out how to have the backpack be "open" I think is where I am getting stuck.

To make the backpack I am using the sketch Doug posted in the templates gallery.
Any help is appreciated!

There are some cakes in the galleries that are makeup cases with makeup coming out of them; and other cakes that are bags with candies coming out of them; and I think I saw grocery bags that are spilling their contents. Those may help you envision the "spilling" aspect of your cake.

i see it with the backpack on its side with the things spilling out onto the florr