I've been a fan of Rube Goldberg's drawings of overly complicated inventions since I first saw one. Now, through the magic of the iPad and Rube Works ($2.99), you can recreate some of his inventions, using an elegant, sophisticated interface.
If you're not familiar with Rube Goldberg, you owe it to yourself to do a Google search. Basically, he takes simple tasks, like an alarm to wake you up, and combines a plethora of obscure devices and even animals to accomplish the task! Rube Goldberg machines are far more complex than they need to be, and that's the point.