Penny loafers were first manufactured in the 1930s with a sleek, simple design that many still know and love today. Shortly after the shoe's debut, a strap featuring two open lips -- just big enough to hold a shiny copper penny -- was added, and the penny loafer craze truly began. Men started subbing penny loafers for summer flip-flops in the 1960s, wearing them without socks during warmer months. Years later, this trend is still in style, and while penny loafers are often worn with casual outfits, they're also acceptable office attire, too (with socks, of course). Penny loafers are not only a suitable shoe choice for men -- women enjoy wearing these sensible shoes for a wide variety of occasions as well.