This has been my thing for a while, but very few people I have encountered even notice this, and therefore they do nothing about it.
.
The evolution of the cell phone from no screen, to all screen, has left me with increased anxiety over the disgustingness of the phone. You can take a normal person, with a normal amount of oil on their face, and after talking on it, the face of their phone will be gross and caked on with oil and body ash. More often than not, when I see someone using their phone, it has face oil on it, and the person doesn't think twice about sticking it right on their face and in their ear. Needless to say, if I am going to use someone else's phone, I wipe it thoroughly before it gets anywhere near my face or ear. I'm pretty sure I can't catch anything from my ear hole, but that is not a risk I am willing to take. Now don't get me wrong, I'm not saying I'm immune to this vile side effect, but after I finish with my phone call, I wipe the phone on my shirt to remove all finger prints, face oil, and skin flakes from the phone before I put it back in my pocket.
.
Cell phones aren't the only culprit of these crimes of disgust. Landlines can be pretty gross too...if not worse. Landlines can be worse because they have the length to get close to the mouth of the person talking as well as their ear. So not only do you get the oil from the ear and hair, but sometimes you get mouth stank too. Believe it or not, I have talked on a communal phone that actually smelled like the bad breath of the person who was previously talking on the phone. It made me gag. I realize this is not a flaw of the phone so much as the completely atrocious bad breath of my coworker, but seeing as it was an unavoidable situation (brushing of teeth aside) I have to blame the phone. Sorry phone.
.
Anyway, since phones are a necessary part of my work life, I just keep myself aware of my surroundings and wipe the phone on my shirt if needed, even if that means the person on the other end has to wait.