Here are some interesting sites that you might enjoy pertaining to Science and Engineering:

Cells Alive!	Cow's-Eye Dissection	The Visible Embryo
Clever Games for Clever People	Virtual Cave	VolcanoWorld
The Geometry Center	Math Problem of the Week	Interactive Frog Dissection
The Aurora Page	The Science of Cycling	The Empiricist: Journal
The Glacier Project	Particle Adventure!	About Rainbows
About Temperature	Dan's Wild Wild Weather Page	Popular Science