[red is visited, "green" is not]
Sadly, if I were to create the world map version, it would be rather devoid of visited countries (UK, Canada, Grand Cayman, Bahamas, pfffft...). It is on the todo list to fix that.
Chris Pavicich has put together a very cool little Finder CMM (contextual menu) that adds Subversion and CVS support to the context menus popped up within the Finder. It is open source and available for checkout/browsing. A prebuilt binary is also available.
I have had a look at the code and there is some neat stuff going on (beyond that it "just works). In particular, Chris is using both Objective-C and Cocoa within a Finder plugin. I didn't know that was possible, but am ultimately not surprised given the work that was put into Cocoa/Carbon interoperability.
Still needs a bit of refinement, but is already quite useful. I will certainly be tracking the devleopment of this and will keep a fresh copy built in ~/Library/Contextual Menu Items!