If you save your empty Cardboard Egg Cartons, they make a dandy place to start Seeds in early Spring.
I tried this a couple of times and it works fine. Pressed Cardboard Egg Cartons, as opposed to the Styrofoam ones, allow water to seep right through and does not hinder root growth. They work just as good as Pressed Peat Cups, only Cardboard Egg Cartons come with a dozen eggs that you can enjoy before recycling them for Garden use. Poke a few holes in the bottom, tear them at planting time, and they can go right in the hole.
Most Cardboard Egg Cartons are made from Recycled Paper to begin with, and when you use them for Gardening, you recycle them again. One Egg cup at a time.