The Baz Bus is a great way to get around Southern Africa. It has a "Hop On, Hop Off" policy that really works for those not on a fixed time schedule.
Basically you buy one ticket that will cover the area you are interested in and get on or off the bus anytime or anywhere you want. A day, or at most two days later, another bus will come along and pick you up if you're ready to go.
This Journal will cover a one day Cape Point Tour they offer, and coverage of travelling up the Eastern Coast of South Africa from Cape Town to Kruger Park