Science at TeacherVision (Animals, Dinosaurs, Earth Science, Human Body, Inventions, Oceans, Planets, Rainforest, Space, Weather and More) http://www.teachervision.fen.com/lesson-plans/lesson-7167.html?detoured=1
Science at EdHelper http://www.edhelper.com/Science.htm
Great Science Links http://www.esu7.org/~sgsweb/greatscience.html
American Museum of Natural History Teacher Resources (including lots of student activities!) http://www.amnh.org/education/resources/ology/ology_index.php
Logal Science (hands-on science topics) 30-day Free Trial http://www.riverdeep.net/registration/resgister_trial.jhtml?cameFrom=
Riverdeep User's Guides and Manuals: Logal Science and more! http://www.riverdeep.net/support/man_and_guides.jhtml
Science Resources at Scholastic.com http://teacher.scholastic.com/activities/
McGraw-Hill Science (Grades 1-6) http://www.mhschool.com/student/science/mhscience02/index.html
Discovery Kids http://kids.discovery.com