Well done; you have taught your Pi to say "Hello World"! However, we are sure you can do more, much more. Have you watched the movie Close Encounters of the Third Kind? Well, if not, you should. However, this is not a challenge in itself. In the movie, the human beings attempt at communication with what they believe is aliens by building a pattern of lights that are set to music. Can you make a pattern of LEDs repeat that or something similar?