When it comes to teaching Bayesian reasoning, I am always searching for new ways to relate the process of formal belief updating to students. One idea I had, was to use something that is no doubt on the minds of many students most of the time: their grades.
This worksheet (pdf) allows students to place prior probabilities on their grade outcomes in a course. They can then use their observations (grades on assignments, quizzes, etc) to update their grades probability distribution. As my students use R in the lab, they can then plot their posteriors as the course progresses. The exercise can also be used to explore the idea that any prediction/inference made in this way is always conditional on the model.
Feel free to try it out in your class!