In terms of raw impact, probably smartphones and social media. (No, these aren't strictly new within the last 20 years, but approximately so, and most of their

In terms of raw impact, probably smartphones and social media. (No, these aren't strictly new within the last 20 years, but approximately so, and most of their impact came from their widespread adoption within the past 20 years -- roughly since Facebook and the iPhone.) A lot of other innovations within the last 20 years are downstream of these -- e.g. no Uber without smartphones. Whether these had a net positive impact is a totally different question. Smartphones arguably enable a totally different relationship with the physical world: effortless navigation in unfamiliar places; dynamic social interactions in the real world, etc. And while we all partake of this to a certain degree, it seems to have been offset to a large extent by the negative influence of living more online. Beyond that it's hard to think of inventions within the last 20 years that have really changed our lives. Personally if I woke up tomorrow and was back in a world with 2003 technology, I'd probably feel minorly inconvenienced, but not fundamentally worse off. (Admittedly I'm a fairly unsocial person -- the past 20 years of tech didn't do much to change that.)