From the Walkman to the bra, these are the innovations that have changed all of our lives. But what is number one on the list? The gadget: It's small enough to hold in your hands. It's mechanical or electronic and mass-produced. It's a personal item that evolves from novelty to necessity and ultimately shows its paradigm-shifting power. In this entertaining programme, a diverse panel of hand-picked experts join forces with HISTORY to rank the most influential inventions of the past 200 years and tell the surprising stories behind them.