I did this awesome prayer service with my 8th grade religion classes a few weeks ago. In a "magnetic poetry-esqe" fashion, I blew up print from all sorts of different books and bibles. The kids were to let the words pick them so-to-speak and the prayer poems they created were phenomenal! They were not supposed to worry about grammar, etc.--just go with the Spirit.
I made a little video on them to share. I did this video in 20 minutes, so it's not my best quality, but you'll get the picture. The song is from Casting Crowns--If We are the Body. Enjoy the work of the Spirit through these 8th grade wonders.