Knitting towers, knitting mushrooms, knitting Nancys and knitting Neds. Corking, or French knitting as it's sometimes called, is a very old-fashioned craft for kids. Kids can start doing it as early as about 4 or 5. Basically, as soon as they have some patience for sitting and good fine motor skills.
It's a great quiet activity for a sick day, when younger siblings are napping, or Mom is having a Calgon moment. It would probably work nicely in church, a waiting room, or on a long car trip, too. Give it a shot and see if it's something that speaks to your little people.
You can buy some pretty neat knitting towers--like this double-sided tower and this mushroom tower. And check out Spoolknitter, a very cool Flickr group of people who collect old fashioned knitting Nancies. We didn't want to spend any money or have to wait, so we made ours with 4 popsicle sticks, a TP roll and some masking tape. Very simple.
I wanted to get a shot of Huck working on this but never seemed to have my camera handy. I also wanted to do my own video tutorial for it but, honestly, I have other things I need to be doing right now besides figuring out how the heck to do that. So, here's the knitting tower video we learned it from and a photo tutorial that also good.
Finger Knitting (how-to here) is also very fun. In fact, I prefer finger knitting but Huck likes working on the tower better.
Knitting is one of the only activities that uses the left and right sides of the brain simulanteously. In Waldorf education, all children are taught to knit in first grade. It's believed that knitting is good for the development of finger and hand muscles needed for writing and also for math skills. I have no idea about all that, but I do know this much...when Huck is working on his knitting tower, he's not talking.
And those are some priceless minutes in my day.