A little house for your rock buddy!
I actually did this ages ago... didn't find out about the project until about a day ago!
Glue the fabric to the bottom and the wallpaper to the sides.
Arrange the doll furniture in someway that you like. You could make a little hammock, or make a little teddy for it. You could glue the furniture to the floor, but that wouldn't be very easy to move, would it?
Put your rock buddy in it and show it off to all the "popular" people in your class- shame on them they don't have a rock buddy!