Five Most Useful Inventions

Wow...this one is a little boring.

agriculture
Neolithic populations gained control over food supply, allowing them to settle down and begin the real work of inventing. While settlements might have cost humans in health for millenia, we eventually learned all kinds of hygiene and health lessons. Some, we are STILL learning.

writing
Writing is something we, in the computer age, take for granted. What incredible imagination was involved in creating written language so that information could be preserved? Even more, things like the Rosetta Stone demonstrate forward thinking in multilingual translations in 196 BCE.

germ theory
It wasn't until the 1800s that we realized that most communicable diseases were caused by "invisible" germs. The simple steps of hand washing cut down significantly on the mortality rates. Who'd have thought that soap and water would do more than just make you smell better?!

climate control
I am thinking about the ability to create and preserve habitable environments, such as in a submarine, airplane, or space lab. We even have individual environments, such as scuba suits or space suits. Figuring out how to create moveable human environment has enabled us to explore "where no one has gone before," from the depths of Earth's oceans to the surface of the moon...and someday, beyond.

Internet
Maybe cliché, but I think the Internet is comparable to the printing press. It is an incredible tool that has enabled billions of people access to information, from news and science to entertainment and social outlets. This is one of those inventions that is truly changing the world as we know it. Neuropsychology postulates that such changes are in fact re-wiring how the human brain processes information. You've probably noticed that you don't remember phone numbers, partly because you don't have to. It isn't because you're going senile; you simply don't use that part of the brain as much anymore. It is likely that we will literally not understand how the next generation thinks...their brain patterns will be so very different from those common today. A lot of that is because of technological advances and global information sharing.