Should we all be a little bit crazy? Today's inventions may seem impossible or pointless, dreamt up by people with extraordinary minds - but they could soon be changing the way we live.

The tail of the car extends. A wing folds out on either side. In just two and a quarter minutes, his flying car is ready to take off on its 300-mile journey.

This scenario is close to becoming a reality. On Monday, a hybrid car-aircraft completed a 35-minute flight between two airports, Nitra and Bratislava, in Slovakia. On landing, its inventor, Professor Stefan Klein, drove it straight off the runway and onto a main road. His journey, he said, had been very pleasant.

His AirCar has a BMW engine and runs on the same kind of petrol as ordinary cars. It can carry two people and fly around 600 miles at a height of 2,500m.

The idea of a flying car is far from new. In 1940, Henry Ford declared: "Mark my words: a combination airplane and motorcar is coming. You may smile, but it will come." In 1964, Ian Fleming used it as the basis of his classic children's book Chitty-Chitty-Bang-Bang: The Magical Car.

In some respects, the notion is completely crazy. Things that would cause a problem in an ordinary car - breaking down or running out of petrol - would be fatal in the air.

Finding places to take off and land would be a major challenge. And in any case, the last thing most people want to see is a build-up of traffic in the sky - particularly when climate change means that we need to cut carbon emissions.

But many things that are commonplace today were once considered mad. In the words of a famousVery well-known. song, "They all laughed at Christopher Columbus when he said the world was round; they all laughed when Edison recorded sound." However weird some recent inventions might seem, they could yet prove to be successful.

Bonkers conquers

Take the Necomimi - a set of mechanical cat ears that you wear on your head to measure brain waves and detect your mood. If you are relaxed, they droop; if interested, they perk up; if focused, they wriggle.

Possibly more useful are LED slippers, which have tiny torches in the toe to guide you around the house at night, and the Baby Mop, which consists of mop heads attached to a onesie so that the child wearing it cleans the floor as it crawls around.

Kitchen equipment includes the cutting-board bird feeder - a table with holes in it and a tube underneath, so that the crumbs produced when slicing bread are carried to a small container where birds can peck them up. And when done slicing, you can put your sandwiches in anti-theft plastic lunch bags, which have green blotches printed on the outside to make it look as if the contents are mouldy and not worth stealing.

Finally, there is the ping-pong door, which opens downwards as well as sideways to create a surface for playing table tennis.

Should we all be a little bit crazy?

Some say, yes. It is only by attempting things that seem mad or impossible that leaps in human progress are made. The greatest genius ever, Leonardo da Vinci, designed a flying machine long before the technology needed was available. Many people find James Joyce's novel Ulysses almost unreadable, but it is credited with revolutionising modern fiction.

Others argue that it is far better to be sensible. It is no good coming up with extraordinary ideas unless you have the help of people with their heads screwed on to put them into practice. The ideas most likely to catch on are those that make everyday tasks easier, like the ballpoint pen or a vacuum cleaner with no bag to remove.