I stumbled on a book at the library about Salt Dough, and it seems like it would be the perfect kid crafting activity. Apparently Salt Dough is a make-at-home modeling clay created from flour (2 cups), salt (1 cup) and water (3/4 cup). I love that no special ingredients are needed. Just mix ingredients, knead, shape and bake.
Next time we're stuck indoors and need a fun activity, I hope to bust this one out.
More details on the recipe and a video demo can be found here.