There's an interesting report here from the UN Foundation and Vodafone, talking about mHealth, that is applications of mobile technology to health problems in the developing world. Because mobile has grown so fast, and costs have fallen rapidly, the mobile phone has leap-frogged the land-line and the personal computer and rapidly become the most pervasive communications device in places like Africa and Latin America. Land-lines will never catch up now (because the infrastructure cost is too high), and in terms of personal computing, the phone is the first computer many Africans will see, and in many cases the only Internet-connected device. The UN report shows that there are approximately 10 times as many mobiles available as computers, so the potential effect is profound.
But mHealth is not necessarily about the Internet at all, and in fact many of the successful applications are delivering value through basic voice and text functions. One example is disease tracking, where field workers can report malaria outbreaks, or cholera spread using IVR or text-based applications. This allows quicker central understanding of what's happening in the population, and allows a meaningful medical response. Another example is in communication of health information. Where there are few health workers addressing the needs of a large and distributed population, it is not possible to reach everyone in person to communicate information about staying healthy. SMS texting is a useful channel for sending information out widely, without depending on people visiting clinics. The report also talks about remote monitoring, where TB patients are given mobiles so that remote health workers can monitor their condition, and also remind the patients to take their drugs. The evidence shows that compliance of patients is greatly increased, meaning more chance that they will make a recovery, but also (importantly) pass on the disease to fewer others.
A lot of the tools that we have available through phones (IVRs, USSD menus, text, voice SMS etc) look primitive compared to the kind of communication available to Internet users in the richer North of the planet, but it's easy to overlook the radical effect that simple technologies can have on the poorer communities of the World.