Rules Discussion: Resource Conversion

Lewis & Clark has some nifty mechanics interwoven into a fine racing game; one such mechanic is resource conversion for movement. Basically, in order to advance up river or mountain spaces, you need one or more characters that convert resources to movement, and you need characters or Native Americans to gather the resources you need. The key is to find the characters that most optimally convert resources to movement. At the start, everyone gets a mission commander, who can convert two food into two river spaces, one canoe into four river spaces, or one horse into two (?) mountain spaces. This is the bare minimal conversion rate, so you have to keep your eye out for characters who convert fewer resources into more spaces. For example, one character converts three wood into four river spaces, which cuts out the "conversion to canoe" intermediary step. Ultimately, Lewis & Clark boils down to setting up an efficient resource conversion engine.

Resource conversion is prevalent in European games. Two examples I can recall are Uwe Rosenberg games: in Le Havre, you process simple resources into things like smoked fish, steel, and coke; and in Agricola, you can convert wood, clay, or reed into food with the right occupation or major improvement. I'm not counting using resources to build final products, such as in Stone Age, in which you convert resources to huts or civilization items, or in Puerto Rico, in which you convert cargo into victory points (though it is a kind of conversion), but changing one resource into another is common to Euro games and a welcome, time-honored mechanic.

Do you have any examples of resource conversion to share?