Whiteboard
Whiteboards became commercially available in the early 1960s, but did not become widely used until 30 years later. Early whiteboards needed to be wiped with a damp cloth and markers had a tendency to leave marks behind, even after erasing the board. Dry-erase markers for whiteboards were invented in 1975.
Billboard
The first "scented billboard", an outdoor sign emitting the odors of black pepper and charcoal to suggest a grilled steak, was erected on NC 150 near Mooresville, North Carolina by the Bloom grocery chain. The sign depicted a giant cube of beef being pierced by a large fork that extended to the ground. The scents were emitted between 7–10 am and 4–7 pm from 28 May 2010 through 18 June 2010.