Non-linear storytelling taken to an entirely new level - HBO's Imagine

HBO is more.... What? Everything! Check out their site and the strange interactive story Art Heist, which you can choose to view from any angle. The "cube scenes" which play from multiple angles at once, reveal hidden events which require you to view the scene from all angles to get all the details, and move forward in the surprisingly layered plot. If you get lost, there's a "chart your progress" navigation button at the top of the screen.