paper cuts hurt, cardboard cuts HURT, but what sucks the most is when you buy something in a sealed plastic container, like a compact flash card or windshield wiper blades, and you cut your finger in the process of trying to rip those open...
i have a filleted (sp?) index finger on my left hand cuz of trying to open a CF card and CF reader today that were packed in those crazy hard plastic sealed thingies...
just remember, if u get a paper cut, don't suck on it... the bacteria in your mouth will up the chances for infection