Emily, her friend Becky, and I did a cool little science experiment this past weekend called the bouncy egg. Basically, you soak a raw egg in white vinegar for 20 hours or so and during that time the shell will disintegrate leaving an intact egg held together by a semi-thick membrane.
You can then drop it from 6-10" and watch it bounce. You can squish it in your hands and even see into the membrane a little bit. It's pretty neat. Heck, even without the kids present I would have had fun with the bouncy egg.
Here is a short video of us playing with the egg and then, finally, figuring out how how it can survive a drop from before breaking (I'd say it survived a fall from at least 15").