东西 (dōngxi) Things

Things that we keep and use can hold our thoughts, memories, knowledge and skills. China was one of the first places a writing system was invented, allowing people to store information outside their brains. We surround ourselves with stuff, reflecting how we think and live--writing, tools, artwork, "smart" devices and the internet, etc. Question: What thing reflects the culture (文化) of students today, and of people around the world in the 21st century? Contributions to this collection should be in Mandarin.