Totally off topic... but I'm intrigued by the question and an article I just read.
I've for my entire life (well as far as I can remember) only breathe out of one nostril at a time, and it switches back and forth. I always thought I was just strange and mildly deformed (shocking right?!?) Then I stumbled upon this by pure chance.
http://www.todayifoundout.com/.....at-a-time/
It claims that 85% of people have the same issue, and well its not really and issue at all but a normal thing called the nasal cycle.
Anyways on to the poll!
(On a side note only once in my life I can remember breathing clearly through both nostrils... It was when I was cooking with balsamic vinegar!)