Today at some stage, Facebook will hit 200 million users - nearly 3% of the world's population. It's another massive milestone for the service, which only hit 150 million back in January. The news means that it leapfrogs Brazil to become - if it were a country - the fifth most populous country in the world. The news has prompted boss Mark Zuckerberg to make a blog post, asking what 200 million means to you. A video's been put together, too, which you can see here, featuring a heatmap that shows where Facebook is most accessed - proving fairly conclusively that it's still an exclusively western phenomenon. If you're interested in more about Facebook, then have a read of my article the other day which discussed why we shouldn't forget about Facebook in all our excitement over Twitter and Spotify.