A lecture to engage students into Computer Science

cpcfoursixfour writes: I'm College Professor and I was challenged to give high school students a lecture to get them passionate about Computer Science. Our 3rd year students are organizing a small summer school for high school students. The idea is to motivate them to enroll into Engineering degrees. This summer school consists of several activities and classes on subjects like Electronics, Networking, Computer Science, etc.
Now, if you were given one hour to get high school students passionate about Computer Science, how would you go about it?