Smithsonian Institute: excellent resources for engaging activities and ideas for integrations of science across the subject areas, cultures, settings.
http://earthscienceguy.blogspot.com
GREAT ideas you can use right now to teach all areas of science.
http://learningcenter.nsta.org/
Web site subscription available to get frequent alerts of interesting celestial phenomena.
Highly engaging resource for students and teachers. Sharp, cheery, funny graphics with real science embedded.