Okay, I went and found the website and found several others with the same recipe for homemade Moon Sand. (I have put this recipe under the how to pages under recipes for easier access rather than suffling through a bunch of posts.)
6 C. play sand (the very fine type)
3 C. cornstarch
1 1/2 C. cold water
Mix cornstarch and water thoroughly until it is completely smooth and mixed in. It'll take a few minutes.
Gradually mix in the sand 1 cup at a time. You'll really need to work it in with your fingers.
Play with it!!!
When you're done put it in an air tight container.
To revive it to play with it again just sprinkle 2-3 tablespoons of water on it and work it in.
You can use food color to dye the sand OR you can buy colored sand. I'm not sure what the cost difference is if there is any as I have not looked. I know Home Depot does carry the play sand though if you have one near you but if you don't you should be able to find it or get it through a home improvement store like that.