suppose I parachute into mainland Africa, could I help the people with my Hacker skills?
aneesh: You can work with others.  Develop point-of-sale software to improve efficiency at crowded stores.  Cell phone software can make markets more efficient and prevent price-setting that farmers suffer from.  Then there's medical records software.All of these 1) require some domain expertise, even if small 2) are conceptually simple, but the delivery is hard