Dishwasher, plastic utensils, spoons, etc.
My son loves to play with the dishwasher while I am cooking dinner. When the dishwasher is clean, I put all of his plastic spoons and forks in the silverware holder and let him practice taking them in and out. I also include our stainless steel spoons since he loves 'big people' items. He can sit there and play for up to an hour sorting and resorting the utensils. Conceptually, it challenges him to think about how to pull long objects out of narrow spaces.