I recently had a chat on an airplane with a Thai horticulturalist who had started some guava plantations in Nigeria. He was a most impressive Thai entrepreneur. One thing he mentioned was that there were one million Chinese people living in Nigeria (a fact which I had not been aware).
This week The Economist has an article about the impact of Chinese businesspeople on Africa. I beleive this could be one of the most important -- and most under-reported -- developments in the recent history of the continent.