I've recently become addicted to the Cornell Ornithology Lab here at this SITE. The site features live streaming of two web cams set up - one watching a red-tailed hawk nest and one watching over a blue heron nest. Both nests have fairly recently hatched young that can be observed. I took screen shots of both nests above. You can even ask questions online to volunteers who man the IM board.
I showed them to a second grade class I was covering and I had them make inferences about the weather, habitat, and eating habits based on what they could observe (the red tail hawk usually has some dead mouse or bird in the nest which always makes a site much "cooler" in the eyes of the kids).
Careful when watching...it is VERY addictive :)