I forgot to mention it the first time around, but the always-insightful podcast series from the BBC, African Perspectives, has re-released their episode on the lives of Liberian rubber tappers on the Firestone plantation.
As of the date of this post, there are two weeks left to download it directly from the BBC website. If you're reading this and don't see the podcast at the link above, I think it be more or less permanently available on iTunes, especially if you subscribe to African Perspectives, which is a good idea generally.
The mini radio documentaries are generally just under 30 minutes in duration, and span the continent from interviews with African first ladies, investigative reporting as to why the Congolese army commits so many rapes, to how a centuries-old Chinese shipwreck was found off the east coast of Africa.
Incidentally, the BBC also provides a daily collection of their reporting from Africa, from Egypt to Liberia to South Africa, in a daily podcast called Africa Today, usually about 15 minutes long as is issued every weekday.