Typically, only a fundamentally new way of 'looking at things' will really make a difference and stir new development. Not all innovation is based on whizkid ingenuity, however. Some of the 20th century's greatest ideas were actually based on plain common sense. Click on pictures to enlarge.
For instance, did you know that the concept of using swept wings - setting the wing at an angle instead of perpendicular to the airplane's fuselage - to reduce high-speed drag, was first developed in Germany in the 1930's? About thirty years after the Wright Brothers took to the sky for the very first time. Next came making wings thinner than the usual airfoil. Now we say: wasn't that obvious? Why didn't they come up with those a little sooner? Left: Messerschmitt ME-262, one of the first swept-wing (fighter) planes.
Moshe Safdie, the Israeli architect of the Marina Bay Sands Casino in Singapore, once told that someone had put a shelf on top of a mock-up of skyscrapers and left it there, probably during cleaning the office. That inspired him to top tall buildings with a horizontal element. It dawned on Moshe Safdie that high rise forced planners, architects, builders and office people to think and work vertically, in stead of laterally, which is the more natural, down-to-earth way of doing things. The landmark Casino was completed in 2010. You might say that high-rise constructing came full circle more than a century after the first skyscraper, defined as a steel-framed concrete construction, basically a bridge built vertically, was introduced. 
Did you know that so-called sloped armor - armor plating that is 'angled' backwards - was first used in World War 2 (approx. 25 years after the first tank was introduced during WW1)? Sloping an armor plate makes it harder to penetrate for anti-tank weapons. A projectile hitting a plate at an angle other than 90° has to travel a greater thickness, compared to hitting the same plate at a right-angle, and has a greater chance that it will get deflected. A simple idea, but the German Tiger didn't have sloped armor. The Russian T-34 tank you see on the left did. The same applies to "Elementary, my dear Watson" reactive armor, which signified the next big leap.
The notion of geostationary orbit
- objects flying at a predetermined altitude and velocity that keep
them within the earth's gravitational pull in a fixed position - was
first disseminated on a wide scale in 1945 by SF- writer Arthur C.
Clarke. Yep, that is the same man who co-wrote on Stanley Kubrick's
'2001 - A Space Odyssey' movie. Without satellites circling the planet, worldwide communication and broadcasting would have been unthinkable. 
Shipping containers - weren't those obvious? Haven't we been trading, mass-transporting goods for the better part of the 20th century? Yes, we have. Nonetheless, it took until way after WW2 before trucking company owner Malcolm McLean introduced the modern intermodal container. Containerization dramatically reduced transport costs, changed the face of international trade, and formed a major contribution to globalization. It did away with the manual sorting of most shipments and the need for warehousing. Containers have standardized dimensions. They can be loaded and unloaded, stacked, transported efficiently over long distances, and transferred from one transportation mode to another - container ships, rail transport flatcars, and semi-trailer trucks - without being opened.
Like the Mini, New iSetta is a concept that brings together many new elements. To be able to create a sleek shape (one of the biggest contributing factors to boost energy economy) whilst maintaining safety standards, passengers don't sit next to each other. The old Romans already knew that arches make for a stress-resistant construction. New Isetta has a Da Vinci-inspired cigar-like frame underneath the outer panels and a dual-purpose rear cowling, covering the twin wheels and integrating a flush-mounted rear bumper (a safety feature too). Lighter materials can be used. Besides, a vehicle that hinges on its (clustered) rear wheels displays
virtually no flex, contrary to a box resting on its four wheels. Space-efficient use of the infrastructure is a nice bonus. New Isetta will carry three persons more safely, economically and comfortably than a VW Polo, Opel Corsa, Renault Clio, etc. can. The passenger configuration depicted above is the UK version's, i.e. with the driver seated to the left (the EU/U.S. layout is depicted below). Why? NCAP crash testing.
