What can soap boxes, sweet wrappers and tin cans tell us about our shopping history? Manuela Saragosa visits Robert Opie at his Museum of Brands, Packaging and Advertising in west London. He's been keeping discarded items and packaging since he was a school boy - well over 50 years. In the process he's created a collection that charts the retail revolution of the past century. It's one that showcases how the whole idea of branding and packaging evolved and tells us something about how we once lived.