Daddy put clean new sand into the sand box, and it has been the main focus for the kids this week. We've had elaborate sand castles, pirate treasure hunts, and lots of cars and animals involved.
Baby B is reluctant to get into the sand (he doesn't like the feel of sitting in it) so to get him involved I made some texture cards. I just took stiff cardboard and cut different shaped grooves or waves into one side. I showed him how to move it across the sand and make different patterns.
This was a huge hit - a way he could play without getting INTO the sand. (You can buy toys to do this, but this was a spur of the moment idea and I had the cardboard on hand.)