Buying a book, lamp or new computer online is easy. But without a dressing room, buying jeans that fit can be a challenge. Enter zafu, a new site meant to help women find jeans from major name brands that match customers' style and shape. Zafu takes you through a series of questions designed to pin down various aspects of your body shape and your desired pair of pants — everything from your size and weight to how much your jeans typically gape at the waist — then shows a list of options with links to buy from merchants' websites. It's a long-overdue fix to fashion e-commerce.