Swedish linguist Mikael Parkvall created this map using the relative size of regions to express how many languages they have produced. Papua New Guinea is quite a linguistic superpower. Aaron Hotfelder explains why:
Deep valleys and unforgiving terrain have kept the different tribes of Papua New Guinea relatively isolated, so that the groups' languages are not blended together but remain distinct. While the country is thought to have over 800 living languages, some, like Abaga, are spoken by as few as five(!) people.
Link via Marginal Revolution