What is the best way to set up Mouse Mayhem on someone's computer?

Wait for the victim to step away, then run Mouse Mayhem and select a preset action that will be believably annoying -- random double-clicking is a great choice because it looks like a malfunctioning mouse button. Once configured, the program runs in the background. When the victim returns, their mouse will start acting on its own. The setup dialog only appears once at launch, so there is no visible evidence after that.