A year or so ago Kit's big sister (who was 11/12 at the time) did lots of origami with Kit's (and her) Dad. They got the patterns from Activity Village, so well worth considering as an activity if you are stuck for something to do with the kids over the holidays.
I was using origami to make boxes. Using a pattern from the book 'Origami for Children' by Mari and Roshin Ono.
I'm experimenting with ideas on how to package stock for craft fairs. I should probably concentrate on constructing the stock more to start with!