I love it when seemingly humble household items have an interesting design story behind them. The Zeroll ice-cream scoop (I wrote about it in FT House & Home 21st February) is a great example of this. It has heat-conductive fluid in the handle which transfers heat from your hand to warm the blade thus enabling you to roll and release balls of ice-cream more easily. Intended for commercial use in ice-cream parlours (the more you use it the better it works) it has become a favourite with ice-cream afficionados and food bloggers.