The most unusual of the invention of the past. People do not lose time on the computer, they are embodied ideas.
That's what they did:
Family bike with a sewing machine (USA 1939)
Nogosiped (USA 1934)
Amphibious bicycle, you can ride and on land and on water, the maximum "load
Motoloshad useful for learning to ride a horse (Italy, 1933)
Unicycle bike a top speed of 150 km / h (Italy, 1931)
Hat radio (USA 1931)