My dads collection of punch cards are a favorite childhood toy of my family. You fold some of them in half and those can be walls/corners, and the flat ones are roofs, and you make these giant multi-story play houses out of them and then perch your lego people everywhere, and then collapse them by shooting with rubber bands. Such a fun memory.

Now I look at them and amazed to see some are filled with my dad's FORTRAN programs. It's so fun.