There are plenty of things we take for granted in our everyday lives. Designs and the problems they solve are among the top.
Egg cartons: originally designed to settle a dispute between a farmer and a customer when the majority of the eggs he bought would arrive broken. This carton which cradles the eggs and is snug but soft solved a problem for both sellers and customers.
Locks and keys: people value their security and privacy, and locks and keys help people protect their possessions and information. Today the lock and key goes beyond a physical one which secures to include a digital one which safeguards information which is arguably more vulnerable on the web than in real life.