Discovery Channel's Science Fair Central http://school.discovery.com/sciencefaircentral/scifairstudio/
Describes what an intermediate science project should be like http://www.isd77.k12.mn.us/resources/cf/SciProjInter.html
Dr. Shawn's Super Science Fair Support Center. Student Idea Exchange http://www.scifair.org/studentideaexchange.html
Science News For Kids: Science Fair Zone http://www.sciencenewsforkids.org/pages/sciencefairzone/topics.asp
Science Fair Projects & Experiments http://www.juliantrubin.com/fairprojects.html
This page has links to summaries of middle-school level science projects in the 2006 California State Science Fair. They are PDF documents of the project ABSTRACTS (summary). http://www.usc.edu/CSSF/History/2006/Panels/index.html
SCIENCE FAIR PROJECTS: A good jumping-off place for ideas! http://www.ctsciencefair.org/
Science Project Resources http://www.science-projects-resources.com/
All Science Fair Topics http://www.all-science-fair-projects.com/
Science Fair supplies and some good project suggestions http://sciencefairproject.virtualave.net/
Don't be fooled by this list, click on a date to get detailed steps on many experiments. http://youth.net/nsrc/sci/sci.index.html
Science Project Ideas from Factmonster http://www.factmonster.com/spot/sciproject2.html
Free Science Fair Project Ideas, Answers and Tools for Serious Students http://www.sciencebuddies.org/
Internet Public Library: Science Fair Project Resource Guide - this has a lot of links to some good places to find ideas for topics http://www.ipl.org/div/projectguide/choosingatopic.html
Bouncing Explanation from the Exploratorium Museum - page 3 is very good! http://exploratorium.edu/sports/ball_bounces/index.html