The real South African Fast Food ™®© is makota, a Ngunification of 'quarters' and so called because they are made with a quarter of a loaf of white bread.
The kota (singular) is made with the aforementioned quarter-loaf which is hollowed out and filled with a variety of ingredients of the customer's choosing. Some ingredients have arcane names, completely impenetrable to the uninitiated. The basic kota has cheese and "French" (french fries). From there, you can add "Russian" (a peppery sausage - almost certainly not from Russia), "Vienna" (another variety of sausage), chutney and any of another half-dozen fillings.
At an authentic makota joint, the cheapest kota will set you back R1,50, about 20 American cents (as of October 2007). The most expensive, with every ingredient available, is about R12, or US$1,60. Considering that you're getting a real belt-loosening meal and often a delicious one, the bang/buck ratio is excellent.
An authentic makota joint is hole in the wall. Not a hole-in-the-wall, like a tiny atmospheric café, but literally a hole in the wall of a larger building, exposing a cavity just big enough for two guys, a till and a hotplate. Turning down a residential street to find a queue outside a hole in the wall of one of the houses is somewhat surreal, to say the least.
The first time I was taken for makota, it was as one of two abalungu in a packed kombi speeding back to Jozi from a township school in Soweto. Suddenly something caught the eye of one of the people I was with, who started speaking scamto very quickly to the driver, who swerved into a side street.
"We're stopping for makota." I was told. "It's like black bunny chow" they explained. After everyone buying one, and me buying another for the old, ragged gentleman waiting there who asked but who clearly wanted money for beer, we hopped back in the kombi and sped back home, munching happily. Since then, makota has been indelibly assocociated in my mind with hip, urban, black Johannesburg.
Source: My own meandering experience.