To make one you need about 100 plain white diapers, ribbon, a cake board, cake dowels to stabilize the whole thing and lots of elastic bands. Oh and about 4-5 hours and lot of patience :)
I didn't follow any kind of pattern - I just found building groups of 9 or so easiest...
Once you are done with construction, you can cover the elastic bands with ribbons and hair accessories and some fun turrets and flags...
It looked lovely on the cupcake table :)