In Tanzania there are 3-pin sockets. If you haven't brought an adapter for your plugs you can just use a tooth pick or even better a match. You put the match into the upper hole and push it downwards. This releases the other two lower holes. Then, always holding the match downwards, you can put your plug in the lower holes.If your currecy is not the dollar, don't forget to get as many dollar bills as you can because at the customs only dollar bills are accepted as everywhere in Africa and there are no banks to change money to dollars. Then you are easily given a 3-month visa.