If like me you have the pleasure of wasting your life away in an office everyday then have a look at the toner cartridges that your office printer uses.
They are often packed with a section of 1 inch thick and about 12 inches by 4 inches white foam which make excellent rig boards. Nick some pins out of the stationary cupboard and you have your self nice rigboards for nothing.
I squeeze about 3 of these into a tackle bag and that is more rigs than i will ever use.