Today news is the launch of the ECO in december 2009 to serve as one currency for a " unified market of over 210 million people spread over 16 member countries with a GDP of over $100 billion and per capita of over $8000".

As an business person in Africa such development can only but bring positive expectations for the future.
These nations would have to coordinate their fiscal,labor and investment policies to a certain degree. To remove the headache to start over everytime you move from one country to another would boost foreign and intra Africa investments .
It will also in the long term increase the strength of African businesses as they can literally become real Pan-African businesses that have equally access to one larger pool of labor,financial products and consumers.
An economic market mere size does not suffice to make it a viable one but China, the EU and the United States economies would not be if it was not for their size.

One interesting aspect of this upcoming currency would be its effect on the financial market, two stock exchanges in the region ,Ghana Stock Exchange and Nigeria Stock Exchange, are some of the most performing in Africa. Could the rest of 14 members countries private-investors benefit from it? A private investors in Guinea can easily invest in Ghana, the same way an Ghanaian can in Ivory Coast. Moreover the earning power being different from area to area, investors and consumers might be tempted to spend their income/capital in relatively cheaper zones while avoiding transaction costs and exchange rate risks.

The impact of the introduction of one currency is going to be tremendous and unforgettable, it is truly the best of times to live,work,invest and be involve in Africa.