Italian Functionalist master Enzo Mari has a fascination for everyday objects; we especially like his investment-worthy perpetual calendars. To learn more about Mari, read Alice Rawsthorn's "Enzo Mari: Rebel with an Obsession for Form and Beauty" in the NY Times, which profiles the design giant and his "volcanic rages" at design, architecture, and Western civilization.

Above: The nearly indestructible Plastic Perpetual Calendar is $90 at OK in Los Angeles.

Above: The 12.25-inch-square Formosa Perpetual Wall Calendar with anodized aluminum backdrop and PVC cards; $258 at Unica Home.

Above: The bilingual Italian and English Wooden Perpetual Calendar of beech, ramin, walnut, and maple uses slide-rule-like functionality; 19 inches long and 3.5 inches high; $145 at Unica Home.