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.
Skateboarding
The first skateboards started with wooden boxes, or boards, with roller skate wheels attached to the bottom. Crate scooters preceded skateboards, having a wooden crate attached to the nose (front of the board), which formed rudimentary handlebars. The boxes turned into planks, similar to the skateboard decks of today. 
Skateboarding, as we know it, was probably born sometime in the late 1940s, or early 1950s, when surfers in California wanted something to do when the waves were flat. This was called "sidewalk surfing" – a new wave of surfing on the sidewalk as the sport of surfing became highly popular. No one knows who made the first board; it seems that several people came up with similar ideas at around the same time. The first manufactured skateboards were ordered by a Los Angeles, California surf shop, meant to be used by surfers in their downtime. The shop owner, Bill Richard, made a deal with the Chicago Roller Skate Company to produce sets of skate wheels, which they attached to square wooden boards. Accordingly, skateboarding was originally denoted "sidewalk surfing" and early skaters emulated surfing style and maneuvers, and performed barefoot.
By the 1960s a small number of surfing manufacturers in Southern California such as Jack's, Kips', Hobie, Bing's and Makaha started building skateboards that resembled small surfboards, and assembled teams to promote their products. One of the earliest Skateboard exhibitions was sponsored by Makaha's founder, Larry Stevenson, in 1963 and held at the Pier Avenue Junior High School in Hermosa Beach, California. Some of these same teams of skateboarders were also featured on a television show called "Surf's Up" in 1964, hosted by Stan Richards, that helped promote skateboarding as something new and fun to do.