Americans check their phones about 47 times per day, according to a survey by Deloitte, which affords plenty of opportunities for microorganisms to move from your fingers to your phone.
Sadly, that survey's probably true, judging from all the folks you see at, say, the grocery store who are slowly pushing a shopping cart (if not completely stopped) while yapping on their phone or poking at the screen on the phone. So how many germs do they transfer from the shopping cart handle to their phone (and vice-versa)? Many phones harbor over 17,000.
Scientists at the University of Arizona have found that cell phones carry 10 times more bacteria than most toilet seats.
Oh, and don't use your phone while in a bathroom - when toilets flush, they spread germs everywhere, which is one of the ways some people end up carrying e.coli around on their phones. The cell phone, it seems, is one of the most addictive things in the lives of many people.