The chicken brick: everyone had them at the back of the cupboard but most people could never see the point of them, it's just that they were a symbol of being Habitat-y and fashionable and different from the drab post-war 1950s. It was also a supposedly very healthy way of cooking as it steamed the chicken and vegetables in their own juices rather than drying them out in the oven. Using one was a bit of a faff and they disappeared quite quickly. But what a brilliant piece of marketing by Conran!