Oh, the gross-out factor. What would a sitcom be without it? Well, it turns out that someone has done and published some actual research about "double-dipping", using the same end of the same cracker to get more dip from the communal dip bowl. This same issue was central to a Seinfeld episode some years back. And it turns out that there's actually quite a lot of bacteria communicable from person to person by doing this. Go ahead, read the story, or Wikipedia on the same topic. It's quite a party for the bacteria!