Excellent Science Clips by Grade level and topic
http://www.bbc.co.uk/schools/scienceclips/index_flash.shtml
Comprehensive Sites for Science and other Topics
http://www.enchantedlearning.com/Home.html
http://edtech.kennesaw.edu/web/k-2.htm
http://www.nyelabs.com/flash.html
Plant Life Cycles
http://www.primaryresources.co.uk/online/plant.swf
http://www.bbc.co.uk/schools/revisewise/science/living/
Weather
http://www.wildwildweather.com/clouds.htm
http://www.ucar.edu/educ_outreach/webweather/cloudmatch.html
http://www.weatherwizkids.com/index.htm
Balance and Motion
http://www.bbc.co.uk/schools/scienceclips/ages/5_6/pushes_pulls.shtml
http://www.bbc.co.uk/schools/revisewise/science/physical/12b_act.shtml
http://www.bbc.co.uk/schools/revisewise/science/physical/13_act.shtml
http://www.bbc.co.uk/schools/scienceclips/ages/10_11/forces_action.shtml
http://www.at-bristol.org.uk/Newton/experiment.htm
http://edtech.kennesaw.edu/web/k-2.htm
http://nationalgeographic.com/geospy/
http://ce.eng.usf.edu/pharos/wonders/natural/index.html
http://www.nationalgeographic.com/xpeditions/atlas/
http://www.jayzeebear.com/map/index.html
http://www.apples4theteacher.com/map-of-usa.html
History
(People Who Make a Difference)
http://mrsmacdonald.tripod.com/pwmad.htm
http://www.lockhartisd.org/~elemresource/socialst/people.html