Amusement parks frequently have Homeschool Days in which they offer tickets at a discount. Not an educational activity? But it is if you couple it with amusement park physics! Your children will learn the science behind the rides and they will be more adventuresome when they realize the rides are safer than they appear.
A link explaining amusement park physics can be found at http://www.learner.org/interactives/parkphysics/
You can even expand the learning process to other things you will find at the amusement park. How do they make cotton candy? http://www.cottoncandyexpress.com/madecandy.html
What animals might be at the amusement park? What else is amusement park related that you can turn into a lesson? There are so many options!
Six Flags in Vallejo, CA has their Homeschool Day on November 11th. Check the amusement parks near you.
And remember, fun learning is forever learning!