I am a graduate student working in semiconductor physics. I have been asked to give a presentation to high school girls about my field. The problem I am running into is that the organizers would like me to provide something hands-on that the girls can do relating to semiconductors. I have not been able to think of anything or really find anything on the web. I wouldn't mind doing the hall effect experiment (since that is strongly related to my experiments), but I don't really have access to a magnet I can transport (the one in my lab is quite heavy and unwieldy). Do you have any suggestions as to hands-on experiments I could do or where on the web I could find some? Thanks!