What to see in Silicon Valley

Hey HN! Next tuesday about 10 kids from central Indiana with a passion for innovation will be visiting SF, and Silicon Valley. We will be in the city for about 5 days and are excited to experience technology and innovation in this awesome city. We have already scheduled tours of Facebook, Google, and plan on going to the Computer History Museum. We are interested in maybe seeing some startups or really anything (does not have to be tech related). Let me know if you think there is some place that we shouldn't miss! Thanks!