I've found myself throwing away a lot of these instant soup cups lately because we have guests and they eat these like crazy. It's not unusual to throw away 10 or more of these cups in one day around here. The other day as I was taking out the garbage and they kept falling out of the bag and it dawned on me that these sturdy cups have a use for gardening.
Take a sharp pencil and poke holes in the bottom and you can use these to start your gardening seeds until they grow big enough to transplant into larger gardening pots or into your garden. If you're propagating plants fill it with your favorite brand of potting soil and stick your cuttings in these and cover them with a clear plastic bag to trap humidity. They're sturdy enough to use for starting seeds under grow lights if you have an indoor garden light set up.
If you're an indoor gardener and have small potted plants in a window that may be too cold in the winter place the potted plant inside (make sure you poke holes in the bottom) this cup. The Styrofoam will act as an insulator and keep the roots warmer as the temperature near your window drops at night