As Harry, Ron and Hermione make their escape from the Death Eaters in Harry Potter and the Deathly Hallows, Hermione’s handbag doubles as a moving van. Using an Undetectable Extension Charm, the brainy witch is able to pack provisions for their dangerous adventure inside her purse. Books, food, even a tent are carted neatly along, without so much as a shoulder ache. Think of what it could do for international backpacking trips.