R2D2: Sure, he’s cute, but the flaws in his design are obvious the first time he approaches anything but the shallowest of stairs. Also: He has jets, a periscope, a taser and oil canisters to make enforcer droids fall about in slapsticky fashion – and no voice synthesizer. Imagine that design conversation: “Yes, we can afford slapstick oil and tasers, but we’ll never get a 30-cent voice chip past accounting. That’s just madness.”