A kilt-clad fellow re-enacts Marilyn Monroe's famous scene in "The Seven-Year Itch" to drive home the message of "Things we don't really need but can't live without," in a new commercial for White Castle System. In this particular instance, that "thing" he can't live without is underwear. Another such thing is the fast-feeder's latest premium item, the Mood Cup, which comes in three color-changing versions. The TV spot from J. Walter Thompson USA, Detroit, is running in 14 major markets. Copywriter: Patty Gray. Art director: Joe Fago.