http://andys.org.uk/countryquiz/
(Unfortunately it's biased for English speakers, as the country needs to be spelled correctly).
I managed 110...did OK on Europe, Asia and South America, but very badly on Africa and the Caribbean. But isn't it strange how your mind goes blank... I must have spent 30 seconds trying to remember the name of the tiny country between switzerland and austria... and when I remembered, I couldn't spell it




