First, I owe a HT to Greg Mankiw and Mark Perry for these resources. I hope you can put them to good use.
The resource from Dr. Mankiw is a link to a policy simulation to use with your students. It does model a European economy. This may cause students some confusion: things like VAT (value-added taxes) and higher levels of government spending. Additionally, there doesn't seem to be a way to manipulate monetary policy. Finally, the program is a beta version so may have some bugs. But it's a classic exercise.
The resource from Dr. Perry is a link to a YouTube video-clip of the Milton Friedman Choir, singing about the responsibility of corporations. It's interesting and fun, and a great way to introduce a discussion with the students.
Let me know how these work out for you, and if you've run across anything else that you use effectively.