My friend Paula B. once claimed that bagged lettuce was the most important invention of the 20th century.  I thought it was either the airplane or the semiconductor.  Now there is a new contender.  The gift bag.. Now even a man can give a gift that appears planned and thoughtful and get it done in one minute:

BTW A survey in 1907 found that many people thought that the most important invention of the 19th century was the safety match.  Not the railroad or electricity.