There are two kinds of inventions: the natural steps up from existing tech and then there are the ones that are so transformative we don't even realize how much we need them until they already exist. Today, we want to know your nominee for the most life-changing innovation of the last 100 years.
Perhaps it's penicillin, perhaps DNA sequencing, or, perhaps (meta!) the internet. Whatever it is, tell us about it (pictures too, please) in the comments below.
Image: luchschen / Shutterstock.