Travelling around Southern Africa is fairly easy as there are plenty of formal and informal transport systems. This is an overview of what's available...
Major airlines fly into Cape Town, Durban and Johannesburg on a daily basis. There are many great sites out there to book flights on. Local flights are cheaper if they are booked at least a week in advance. Unfortunately there are no last minute stand-by specials in this country! They normally charge you more.
There are a number of cheap car hire operators in South Africa. Cars for Rent s an excellent choice as they have been servicing the backpacking industry for years.You can find them at www.carsforrent.co.za
There are a number of long distance buses, these are The Baz Bus, Translux, Intercape and Greyhound.
Southern Africa does not have a great railroad infrastructure so travelling by train is fairly restrictive (but fun nonetheless). There are also some really great up market options like "Rovos Rail" and "The Blue Train".