Has anyone had any experience with starting seeds from the recycled paper/cardboard egg cartons? I am wondering if the roots will grow through the paper fiber like they do with the 'peat pots'. (We have had a spell of warmer weather here in the west and I am anxious for the growing season!)

With regular watering the cardboard starts to break down into a bit of a mess. The roots shouldn't have a problem. Of course I've never been very good at starting from seeds and most of mine die young.

I did that for some of my seedlings a few years ago. The cartons usually don't have much room in them, but might be OK for small things. I also had the problem of egg carton collapse. If you have them sitting in a flat or something to facilitate drainage, AND you don't move them while they're wet, they should be OK. I didn't actually plant the seedlings in the egg cups--I took them out. Some roots had begun to go through the walls.