I ran across this blog entry a couple of weeks ago. It's a great description of using a questioning game to encourage students to ask questions. Using the template below (by Sophie Wrobel, geist.avesophos.de) create cubes, put students in groups, and let them roll the die. Then, as a review game, students create questions beginning with the prompt. You're shifting ownership to students for the questioning, and at the same time, by giving them question stems, you are providing support. An excellent idea for motivating students and raising the level of rigor in your classroom.