The problem there is the plural in "countries": there's no obvious one place to invest, and cross-border trade is limited by borders, tariffs and terrible infrastructure.

- South Africa is the richest/most advanced on most metrics, but it's also wracked by crime and labor unrest, and set for continuing major political unrest.

- Nigeria is huge and growing, but corrupt to the point of making legitimate business near-impossible.

- Ethiopia is run by a Communist junta whose commitment to reform is questionable at best.

- Rwanda likes to think they're the next Singapore, but they're tiny, landlocked and in a really bad neighborhood.