My almost-three-year-old has gotten quite proficient at the game of memory. You know, the one where you compete to find matching cards. Not only is he good at remembering the location of the cards, but he can usually name the object or character on each of the cards. So he now can correctly identify Mickey Mouse, Pluto, Goofy, and more. While developing memory skills is a good thing, knowing who Goofy and Mickey Mouse are is not exactly a valuable skill.
I figure if he can learn to identify useless characters, he can probably learn to identify useful objects such as computer components. So I hunted down some sheets of blank 3.5″ diskette labels that had been in the cupboard for years, snapped a few pictures of computer components, and then designed and printed them using OpenOffice Writer. Then I applied the labels to cardboard I salvaged from an empty cereal box.