This is a fun, space-saving way to get some exercise. This door has an insert that pivots in the center and turns into a ping pong table otherwise known as table tennis, but is it still table tennis if you play it on a door?
According to Sarah O of InventorSpot,
"Anyone who inhabits â€œpostage stampâ€ size apartments can appreciate the value of space-saving innovations. And unless you are among the lucky few who boast voluminous digs, accommodating a ping pong table into your living quarters is probably more of a joke than a realistic venture. Enter the ping pong door. Designed by Tobias Franzel, this door functions like a normal one would, but also sports a flip-down inner panel upon which you and your closest pals can battle for the title of table tennis champion. Just attach the net, break out your paddles, and let the games begin! "
Implications - A large part of the population resides in urban areas, creating an increased need for space-saving products that are multi-functional.