Note that these are specific to Mary and Greg, as U.S. citizens who have already had numerous vaccinations. If you're planning your own trip, you should look up the requirements for yourself to make sure you don't miss anything or that requirements have changed.
Country Requirement Cost Length of stay
South Africa U.S. Passport None? 90 days
Lesotho U.S. Passport None? 180 days
Botswana U.S. Passport None? 90 days
Zimbabawe Visa obtained at border US$30 180 days?
Zambia Visa, which we've already obtained Already paid 30 days, can be extended twice in Lusaka for total of 90 days.
Malawi U.S. Passport Free, but 5,000 Malawi kwacha for each 30-day extension 30 free days, 30-day extensions available
Tanzania Visa, which we've already obtained Already paid 90 days
Rwanda U.S. Passport None? 90 days
Uganda Visa obtained in advance (Kigali) US$50 90 days
Kenya Visa obtained in advance (Kigali or Kampala) US$50 6 months
Ethiopia Visa, which we've already obtained Already paid 3 months
Sudan Visa obtained in advance (Addis Ababa) US$151 1 month
Egypt Visa obtained in advance (Khartoum) US$15 30 days