Dug this one up from 2008. Remains both an excellent example of the power of logic on true closed-mindedness and another reason to restore our faith in humanity. 

[youtube http://www.youtube.com/watch?v=QJtjqLUHYoY&w=584&h=390%5D
via Chris Remo
[youtube http://www.youtube.com/watch?v=QJtjqLUHYoY&w=584&h=390%5D