In my daughter's kindergarten they could used modeling clay when ever they were done with projects early. They said it was great for those motor skills. You could put some in a baggie and carry it on your purse for your child to play with in resturants or other waiting times.

A few other ideas: stress ball, tangle toy, braiding.
I always thought it was fun to cut out from the jewlery catalogues and the paper flyers with cats & dogs.

Have fun with everyone' ideas.