Think about it. We take our cell phones everywhere. They live in our pockets and purses, rubbing up against loose change and the receipt from the gas station. We use them almost everywhere, and set them on nearly any available surface – the kitchen counter, the table at a café, a park bench. We even share them with others. We pull them out not only to make calls, but also to share videos, play games, send emails and check on our Facebook friends and Twitter followers. Our smartphones are indeed our constant companions, and they are exposed to many bacteria.