Several illustrations of social dilemmas (and other interdependent games) that can be used in teaching are available on the web. See for some nice examples:
– a youtube video explaining what social dilemmas are: more information
– an interactive demonstration and explanation of the trust game: more information
– an interactive multi-trial simulation of the prisoner’s dilemma that allows you to distinguish between different strategies (such as tit for tat): more information
– several demonstrations on the evolution of cooperation that incorporate multiple strategies in repeated multiplayer settings (from gametheory.net): more information