A: A series of reports and comments from businesspeople has thrown a spotlight onto the explosion in mobile phone use across Africa, a continent in desperate need of new ways to improve its economies, its health outcomes and opportunities for ordinary citizens.

Today there are over 310 million Africans using mobiles, and the proportion of people who can use one has gone from only 10% in 1999 to between 60 and 70%.

Q: And why is this important?

A: Well, the recent Social Impact of Mobiles report found that phone networks were the most effective way to provide affordable internet access to the majority of people in developing economies. Much of Africa lacks the IT infrastructureThe basic systems and services that a country needs to keep it going., such as cabling or fibre optics, that make computers so easy and important to life in Europe or America. And the mobile phone took off in a way that landline telephones have never done in Africa, again because of the difficulty and cost of the cabling.

Q: What's the next stage?

Well, a separate report from the Centre for Global Development predicted that by the end of 2012 most villages would be connected, with a few remaining countries (Guinea Bissau, Mali, Somalia and Ethiopia) poorly served.

Q: OK I get that mobiles are cheaper, quicker and easier to spread. But remind me why this matters?

A: There are a whole range of benefits that come with being connected by phone, especially if it comes with internet access. Imagine being a farmer or trader in a rural area - no more unnecessary trips to the local town. Now you can make and receive orders by phone, arrange deliveries, do deals and get access to banking. Whereas mobile phones apps that get developed in the West tend to be for entertainment, in Africa they have been designed to share agricultural price information, for example, or transfer money easily without bank accounts.

Q: Right, so it's about business benefits.

A: And more. Last week in South Africa, a global conference focussed on how, in regions with inadequate systems, mobile technology can be used to organise and deliver healthcare. For example, mobiles can be used to collect information on disease outbreaks, to help health workers in the field diagnose and treat patients, and offer ill people advice. In East and Southern Africa, HIVA virus that damages your immune system. sufferers get text messages several times per day to remind them to take their anti-retroviral drugs. And in societies where having HIV carries a heavy stigmaA mark of shame or disgrace that sets a person apart from others. In the 16th Century, it referred to a literal mark branded into the skin., anonymous text 'communities' can offer support.

Q: OK, I'm convinced. It sounds totally positive.

A: Yes, it's a rare good news story. But problems remain. There are serious inequalities in terms of who can take advantage of all the benefits of mobile telephony - urban dwellers are in a better position than rural people, for example. And women in Africa still need extra help to get on the networks. "The techno-centric Africa of 2011 bears no resemblance to the miseries of the 1990s... but access to the technologies remain highly skewed," writes Yaw Adom Mensah, an analyst at TelecomAfrica.

Q: What can be done about that?

A: As phones and services get cheaper, the inequalities are reducing. New inventions, like the solar-powered mobile, help. But meanwhile, some charities are stepping in. Cherie Blair backs a programme to provide another 150 million women in the developing world with mobiles. According to the former UK prime minister's wife, who is a human rights lawyer: "By being better connected, women feel safer, find employment, start businesses, access banks, learn about market prices and altogether benefit socially and economically."