Students are invited to write a quiz. It can be in the style of Who Wants to Be A Millionaire, Jeopardy, or even just plain old question and answer style. Students will stand in front of the class and be the game show host. Sometimes my students write questions to ask the teacher, or other times they ask questions to ask each other.
You can use this method to determine student understanding about a topic. When an incorrect answer is given, don't just give out the correct answer -- seize the teaching opportunity! Have students look for the answer themselves.