While reading the forums here, I remembered that I did shared dreaming in first and second grade.
A group of friends and I would experience the same dream every night, and in this dream we would be in a dark forest collecting gems. These gems were floating gems, and it was like being in a video game. Before we went home from school, we would all talk about what kind of dream we were going to experience together, then we would meet in the dream world. I don't have any more details, all I remember is that we would "share" dreams. Haven't done it since I was a kid, though.