In most African nations, radio is still the most powerful source of information - unfortunately, radio is a one-way, listen only medium.More on it at his blog, on mobile phones and activism, and on wiring Africa via mobile infrastructure.
The mobile phone changes that dynamic, allowing people to collaborate in the production of radio. Throughout the continent, call-in shows that invite citizens to talk to political leaders offer a form of direct democratic participation that more developed nations may be envious of. Mobile phones also enable ordinary citizens to perform "sousveillance" - surveillance from the bottom up. This has become important in monitoring elections - citizens with mobile phones can call radio stations and report situations where they are prevented from voting.”
Mobile phones in Africa
I've written before a bit on mobile phones in Africa, specifically as platforms for banking. Ethan Zuckerman gives an interview on how mobile phones can be used for citizen media (like what CNN tries to do, but substantive).