When she was just a junior in high school, Christina Li started a free, annual summer camp (Hello World) for middle school girls in her community in Michigan to teach them computer science (from Web development and hardware programming to app creation, game design, and robotics). Li, now studying at Columbia University, started the week-long camp to encourage girls to fall in love with computer science, like she did, and to do her part to increase the number of young women going into Science, Technology, Engineering and Mathematics (STEM) subjects. The week-long camp brings in female computer engineers from Google, Microsoft, Ford Motors, and the Michigan Council for Women in Technology. Imagine you were trying to get more people involved in one of your passions. What would you do? Not everyone can start a summer camp like Li, but what could you do to use your passion to address the problem?