If you got new gadgets for Christmas you may have an excessive quantity of styrofoam lying around. Instructables user shadowfeet recommends converting those small pieces into a small window planter.
Using one of the side pieces that kept a new laptop from sliding around in the box, shadowfeet lined the bottom with a slab of cardboard and filled it up with dirt and herbs. To keep water from leaking out the bottom, two lids were placed underneath to capture the water, but other than that, it's essentially a ready-made planter. It's a clever use for something we traditionally just toss in the trash. Do you have any good uses for styrofoam packaging?
How to make a laptop box styrofoam herb planter [Instructables]