I think this story from The Financial Post about Somali pirates setting up a "stock exchange" has a lot of possibilities. (HT to Arts & Letters Daily.)
It provides a platform to launch discussions on a variety of concepts. The author examines risk and reward, providing an opportunity to discuss incentives. The story can also be used to discuss markets and other economic organizations (or lack thereof), as well as the rules (institutions) used in the market (from participation to cash to barter). There are even aspects of marginal analysis (cost vs. benefit) that can be brought out with a little discussion of "everyday life" in Somalia. As you're approaching the end of the semester and looking for something to prime their brains for exams, this could be a fun and educational diversion.
I welcome your thoughts and comments.