Name: Flip-flops. Age: They date from 1500BC, although the modern version is adapted from Japanese thonged sandals called zori, brought back by US soldiers returning from the second world war. Appearance: Flat-soled footwear featuring a bifurcated strap with three anchor points. Price: £670. £6.70? I know a petrol station where you can get them for a fiver. No, £670 , or $690 in the US. What? You heard me. Are they wifi-enabled? They are not. Do they walk for you? No, you have to do your own walking. Are the soles made of solid gold? They are made of hard-wearing