Surely I can't be the only one who thinks this is pointless?
As many of you have brought up, once you grasp core programming concepts (and to a lesser extent, certain programming paradigms), picking up a new language is just a matter of learning the syntax...
I pull Python, Ruby, PHP, and various Unix Shell code out of my asshole at work fairly regularly without ever having used them before with just a few Google searches...
I don't think it's fair or completely truthful to say that I "know them." To me, knowing a language is having a very deep understanding of its usage, implementation, and paradigms. It is not just being able to hack some shit together in it--any good programmer should be able to do that with any language.
edit: This topic would be more adequately and meaningfully named "How many programming languages have you DABBLED IN" or "How many programming languages are you PROFICIENT AT?"
...Or we can all make a hierarchy like Nokurn.