I stumbled onto a neat link last night while I was browsing, just thought I would share it. It has everything from railguns, laser communication, lightning dectectors, Hydrogen fuel cells, and several other very neat electronic projects/optics projects. Many of these can be built from household goods. Anyway, just thought I'd share it with you all :-)
http://www.scitoys.com/
Great resource for Science fair type projects, or just fun activities for learning. I think I'm gonna have to try some of them myself hehehehe.