Hi gang --
If your kids like pizza, check out www.pizzafarm.org ! This is a real farm in Madera, CA (just north of Fresno) and it looks great. I printed out a bunch of fact sheets and other goodies for the kids, and definitely plan to make this a stop on our family vacation (we're currently studying California).
The most interesting thing I found was the types of international pizza toppings: mayonnaise, potato and bacon in Japan; pickled ginger, mutton and tofu in India; something called "mockba" in Russia which is a combination of sardines, tuna, mackerel, salmon and onions.
Check it out and have some fun! It's encouraged me to try growing some pizza toppings myself.