Styrofoam Recycled, Sort of

What do you do with all those little Styrofoam 'peanuts' that come packed into cartons so often?  Besides their obvious shipping re-use, why not use them as drainage the next time you're planting house greenery or those herbs you decided to grow inside this winter.  These 'peanuts' are extremely lightweight, yet tough, so they'll hold up under the dirt and provide drainage.  It also makes the pot a lot lighter than rocks used for drainage.