Discuss: What Design Idea Are You Thankful For?

If you're reading this, you probably already subscribe to the idea that good design, however small, can have a resounding impact on the people who come in contact with it and the place it resides. The fact that it's good is also often the reason why we stop noticing it. We want to know what design idea has made a difference for you, consciously or subconsciously. From the use of color in your apartment to the driver assistance system in your car, and the handle on your mug to the glow of your carbon monoxide detector, what design idea are you thankful for?