Another day and another new high figure for Facebook. This time it’s their mobile users who are now at 150 million people according to blog from one of their engineers. That is nearly 1/3rd of their 500 million users. The blog is about their mobile api, but conveniently mentions this new high figure in passing. Sadly it doesn’t give details about which handsets are the most popular (iPhone I would guess), but it does indicate the importance of mobile to social media.