Sitting elbow to elbow with strangers in the movie theatre is nothing new to the average American. However, when you are cramped in a packed theatre and you hear a cough every now and then while watching the movie Contagion, well that's another story. Even if you are viewing this movie in the comfort of your home, your mind will start to wonder about the thousands of hands that could have touched this disk you received in your mailbox this afternoon from Netflix. Then it begins..."What have I been exposed to?" My irrational fear as well as fascination about epidemics first grew after the…