In Ursula Lindqvist's Swedish classes, she has the students "warm-up" by doing an exercise that gets everybody talking immediately.
With the entire class standing up in a circle, Ursula throws a koosh ball to a student and asks that student a question in Swedish. That student answers the question in Swedish and becomes responsible for throwing the ball to another student and asking him or her another question.
Ursula comments that the students like this activity as it decenters the class and allows them to ask questions immediately at the start of class. It gets the students thinking in terms of Swedish and sets the tone for the remainder of the class.