I am surprised that there are not more blow-up beds for sale in South Africa. This is something you see quite commonly overseas, and they are very handy for surprise guests. Essentially, and they are normally supplied with a pump, it is a mattress that gets inflated by an electric pump, and provides you with an instantaneous extra bed in your house. They actually work perfectly and while they are certainly not as comfortable as a normal quality bed, they beat sleeping on the floor! They are also fairly cheap.