Poor Man's Beauty Dish. Around $3.50 or $10 if you count the velcro.
I got creative here.
Materials: White craft foam, sticky back velcro, bottom of a ziploc container, piece of emergency blanket, scissors and spray adhesive. I used a bowl to cut a 12" disc in the craft foam. Made flaps in the center for my sb900. I scored the disc and put pieces of velcro on either side so I could create a relatively bowl shaped disc. I cut the bottom out of the cheapest ziploc bowl I could find, spray adhesived the piece of blanket inside it and attached velcro to a few strips of foam and the back of my new reflector. Works reasonably well as a parabolic reflector or beauty dish if you will.