Now that I've got the book in my hands (with my name listed on the supporter page!) I'm extra excited about the project. There's an online community, too, for when you need some help or ideas.
"Kids don't dream of becoming mathematicians because they already are mathematicians. Children have more imagination than it takes to do differential calculus. They are frequently all too literate like logicians and precise like set theorists. They are persistent, fascinated with strange outcomes, and are out to explore the "what-if" scenarios.
"...mathematics is one of the most adventurous endeavors a young child can experience. Mathematics is exotic, even bizarre. It is surprising and unpredictable. And it can be more exciting, scary, and dangerous than sailing on the high seas..."
See also: Möbius strips activities.
I found this Mobius Story (YouTube). How cool! My kids and I have been trying our hands at making Mobius stories. I've also been enjoying the video maker's blog (Vi Hart).
See also: Unschooling Math.