My husband loves his Coke, and I have found the bottles are the perfect shape for gardening. My garden outside might be deep under snow, but my seedlings are safe and warm inside under their little domes.
I had extra tops so I combined them with these biodegradable pots for a very cheap and easy mini green house. I leave the tops open so any extra moisture can escape.
These tomatoes and garlic chives are already making the air in my house smell moist and clean.