One suggestion I've often heard for people spending significant time in Africa is to bring along several sets of sealed hypodermic needles and syringes. Perhaps even an IV start kit. If you ever do need an injection, you can offer your own kit to at least ensure that the needle and syringe are clean. This needs to be done carefully, of course, so as not to raise the hackles of any drug cops you come across.

My experience traveling in Africa (West Africa, so somewhat different) is that the most important thing to bring is your patience, sense of humor, and a warm smile. Most people, in most places, are nice, and will help if asked.

Oh, and the sense of humor is key if you are taking Larium for malaria profilaxis. That stuff messes with you head!