http://www.nal.usda.gov/ref/science/scinet.htm
(looks good)
http://www.nal.usda.gov/ref/science/scinet.htm
(looks especially good)
http://www.lkwdpl.org/study/sfair/ideas.htm
(This has links to all kinds of ideas for high school projects)
http://www.swsd.k12.pa.us/swhigh/science/science%20fair/scifairexample.html
(more student science fair projects)
http://www.ehr.nsf.gov/ehr/ehr/science_home/html/core.htm
(Science in the home)
http://stores.yahoo.com/science-city/scienfairpro.html
(looks commercial)
Happy surfing. Let me know if you turn up something particularly interesting.