When it comes to inventions, not all are created equal.

Some inventions have literally changed the world and how we do things simply because of its innovation and absolute usefulness.

Unfortunately, some are a bit ill-conceived. While they may seem like a good idea at first, on hindsight, the inventors need not have wasted time on them at all.

Do these make the cut? Take a look and judge for yourself.

Click on thumbnail to view (Photos: Internet)

Ever heard of a Japanese concept called "Chindogu"? It's the art of inventing working inventions that almost serve a useful purpose.

The key word here is "almost", as wonderful an idea as these are, they are absolutely worthless in real life.

The rules are:

1. The invention must be useless

2. The invention must be real, and more than a concept.

3. The invention must be created for daily use

From duster slippers for cats for them to help out with the housework, to umbrella ties, they show why the Japanese are considered to be one of the most inventive people in the world.

Click on thumbnail to understand why (Photos: Internet)

China never ceases to amaze with its quirkiness and creativity. These creative inventors have come up with amazing contraptions which include a mini-submarine, a home-made cannon and a giant bicycle.

Some of these inventions are cobbled together with screws, wires and a huge amount of passion and effort.

Click on thumbnail to view (Photos: Reuters, Internet)