Oh, that is sooo cool, I have 2 kids and we've never done the egg in vinegar trick before. That sounds like a good weekend project!
I would think they'd have to keep you at the school if you do such cool stuff like bring in an incubator and hatch eggs with them! Hey, for LA you could write silly rhymes or stories using chicken idioms like: "Don't count your chickens before they hatch"
Right now my kids are busy watching our broody hen on the new chicken cam channel. My hubby hooked up a nature video camera to the nest box and now we can watch her sit on the eggs. It's a little more action than watching the eggs in the incubator, but not much. It will be more fun at hatching time.