So, I began running out of things to give him to keep him entertained. And finally I resorted to the picture below. I grabbed all the corks I've collected over the years (or maybe just last month - I'll never tell) and helping him sort them into different containers.
Maybe that's inappropriate for a 1 1/2 year old, but did it keep him occupied for 10 minutes? Yes. I'll put that in the W column.