Justin Smith from Inside Facebook shared the latest data regarding the growth of Facebook worldwide (via Lova).
Most interesting is the statistics of Asia, especially India & Bangladesh:
While India has about 60 million internet users only 200,000 of them use Facebook. Whereas about 100,000 Bangladeshis use Facebook out of a total number of internet users of only 500,000 (some claim it is 1 million). (Stat source ITU)
Here is a graph showing the growth of Bangladesh internet users (source):
According to the above stats every one among five Bangladeshi internet users has a Facebook account.