I'm getting little gl baby food jars piling up, and want know if there's something I could do with them?

Have any of you done anything creative or constructive with baby food jars? I feel like they could have some kind of potential before just throwing them away (even if it's in the recycling bin). My other child is three years old, so it seeems like there might be a craft or organizational potential there for him, too.... any ideas?