For example, hisown jeans bear the weathered marksof his keys, which he keeps in his front pocket, and his bag, which tends to rubagainst his upper thigh.
They act as giant petri dishes, where creative types and entrepreneurs rub up against each other, combining and recombining to spark new ideas, new inventions, new businesses and new industries.
Both for what it says about changing attitudes towards aid in Africa, as well as the more familiar chaffing that occurs when pride, philanthropy, poverty and celebrity rub up against each other.
