Plugs
Most guesthouses do have an adapter plug that you can borrow, but the most convenient (and cheapest) is to buy an adapter plug in the supermarket or do it yourself store for a few euros (around 30 Rand). Ask for a two point plug in the supermarket if you cannot find them yourself.
Please note: the world plug that you can buy in the Netherlands usually does not fit on the South African sockets! The sockets in South Africa are of the Type M:
UK plug