BBC tells me that the greatest gadget of all time is the Apple Powerbook 100 (1991).
Rounding out the top five were the Zenith remote control (1956), Sony's Walkman (1979), Motorola's Startac (1996), and the CDI mechanical mouse (1970).
Apple, huh? Take that Bill Gates. In all fairness, I don't think software was included in the definition. Still...snarky me, snicker at the headline.