When United Airlines told Julie Dworkin she didn’t have enough frequent-flyer miles for a trip to South Africa, the Logan Square resident and her boyfriend, John Edel, opted instead for southeast Asia. During the three weeks last summer they spent traveling from Bangkok to Hong Kong by bus, train, truck, bicycle, hydrofoil, tuk-tuk, and foot, the pair were struck by the vast gulf between the haves and the have-nots. In Cambodia, taking a boat to Siem Reap, Dworkin and Edel saw people in rags, living in shacks. Many had only one leg, the victims of land mines. The country’s wrecked infrastructure also led to a harrowing five-hour ride in the back of a pickup truck on a bumpy dirt road to Battambang, where speeding vehicles play games of chicken. By contrast, glittering Hong Kong was a capitalist paradise, packed with luxury shops and served by an extensive public transportation system.