Surrounded by barbed wire, amid hovels made of plastic, cardboard and sticks, children were playing an infectious game of soccer - using trash instead of a ball. Those images of Darfur refugees on CNN "were heartbreaking and inspiring at the same time," said Tim Jahnigen, a Berkeley inventor, musician and music producer. "I saw children desperate to play, living in a world where nothing makes sense and they've been traumatized by irrational violence. In their innocence, they were willing to play with anything." A narrator explained that the children's harsh environment meant that balls went flat almost instantly. Jahnigen had...