This was put together by Christians who are focusing on the religious aspect, but it is still a chilling and well done video. It illustrates just how badly our numbers are decreasing, and hints at the number of babies we'll need to survive. Their answer is to convert Muslims, which is of course a stupid solution, but I still found it worth watching and sharing for the numbers.
[ame="http://www.youtube.com/watch?v=6-3X5hIFXYU"]YouTube - Muslim Demographics[/ame]