Sorry if this has been posted before (I dont remember it and I did try to search the forum)
Its quite interesting. A series of Youtube vids, each up to 10 mins, about a guys quest to go around the world by trading commodities.
The next will load automatically once one finishes. Make sure you at least watch episodes 2 - 4 -its coffee-related. Enjoy!
Around the World in 80 Trades