Vodacom, which operates one of the country's two mobile phone networks, is installing vans equipped with mobile phones. Someone who cannot afford a fixed phone or a full mobile service can buy a telephone number with a voice mailbox. Numbers are advertised in the usual way, and anyone can call in and leave a message in the mailbox.
Messages are retrieved by inserting a smart card, programmed with the box number, into a mobile phone. A text display on the phone lists the messages, and users pay to access the network and retrieve them. If the display indicates no messages and the user does not enter the voice mailbox, there is no charge.
A subscriber can be called direct, and ring out, when his or her card is in the phone. The intelligence in the smart card handles the billing information.
The voice-processing element of the system, supplied by Octel Communications, is more sophisticated than an answering machine. Messages are converted from analogue recordings into digital format and any pauses or interruptions are edited out.
Because the information is stored digitally, details about the call can be converted to text and displayed on the telephone before the message is read back. There is no limit to the length of a message.
This telephone substitute may not be as convenient as the real thing, but Alan Knott- Craig, chief executive of Vodacom (in which the UK mobile phone company, Vodafone, is a leading shareholder) points out that the franchised vans can be installed in a matter of hours, compared to the years it would take to provide equivalent coverage with fixed landlines.
'Community telephone services in the form of voice mail on the mobile network will provide access to reliable communications links at realistic prices for the first time ever. It will make a significant contribution to the economic development of South Africa,' he said.
Providing the community services is a condition of the Vodacom operating licence, but Mr Knott-Craig said it was not subsidised. Although the profit margin is low, there is a high level of use compared to that of individual subscribers.
Since April, around 50 of these phone bureaux have been set up in various parts of South Africa, each with 10 phones. Each phone can handle up to 100 numbers.
The concept of Virtual Telephony was invented in Brazil by Telebras, the holding company for the telephone operating companies.
The Brazilian government has made a commitment to boosting economic development by improving telecommunications networks: at the moment there are 10 million phones among a population of 155 million.
Rather than spending up to seven years expanding the fixed network to allow more people to become private subscribers, the operating companies have concentrated on installing public telephones linked to voice mailbox systems.
The service was officially launched six months ago. Now, small businesses like plumbers and electricians can buy phone numbers and use the mail box to handle incoming business.
The computer system dealing with calls announces the company name and uses computer-generated speech to talk to callers and ensure they leave the right details. These systems are so sophisticated that callers may not even realise the company does not have a phone.
Octel Communications is also installing Virtual Telephony systems in Shanghai and Peking, China, where a mere 0.67 per cent of the population have telephones. Kim Fennel, vice-president of Octel, says this will allow people to communicate even where there are no private phones.