Ask HN: How to keep small kids busy?

Do you have good tricks of how to keep small children (18 months) busy? When they meet other children, they usually play together quite well, but when you are with your kid at home alone, the kid wants your attention all the time (reading the same books a lot of times). Two things that work quite well so far for me: - letting him bring clothes to the washing machine from a larger pile - letting roomba run around carrying things, so he can chase it around

Probably some of you have other good ideas?!