Here are some fantastic science programs for families. Each site lists various programs for age groups.
The Maritime Aquarium at Norwalk:
This aquarium has created marine science lessons; some are for kids of all ages while others target specific grades.
USGS Science Explorer:
Find loads of science lessons in this topical directory by the US Geological Survey.
Center for Interactive Learning and Collaboration:
This site offers daily free, interactive, live-streamed programs for kids in grades K-6. Programs come from universities, zoos, aquariums, museums, authors, and more!
Air and Space Museum, Washington, DC
British Museum, London
Museum of Natural History, New York
National Gallery of Art, Washington, DC
Uffizi Galleries, Florence, Italy
Florence Griswold Museum, Old Lyme, CT
Wadsworth Atheneum, Hartford, CT