Cdli: Science Fairs Homepage

At this site from the Center for Distance Learning and Innovation there's a monstrous listing of possible science fair projects. You can choose from primary (grades 1-4), elementary (grades 4-6), intermediate (grades 7-9), or senior (grades 10-12). Physics, Electricity, Meteorology, Chemistry, Biology, and, as they say, much much more. The site does not provide directions for doing the projects, just the ideas for getting started.