This is a good upcycle as well as a good technique for growing your own veggies when the weather may still be a bit cold -- Cold frame window. Helps you grow vegetables and plants earlier at spring. Good re-use for those old windows!
(((Winter Gardening)) A cold frame with a glass top can give you a growing season, even in Maine, and it's the easiest and most economical way to extend your harvest. Build the one described here, and you're on your way to fresh veggies year round.