Scouring powder and a Brillo pad.
It is all that phone sex.. hard to keep the screen clean with them dirty fingers..lol..jk
I don't have a iPhone, I have an android with a protective screen. I recommend alcohol swabs. You can get a large pack of them at a pharmacy. Same stuff used to sterilize injection sites. Anyway, it gets stuff really clean and evaporates fast. I usually wipe the screen with a cloth after the swab though to avoid "water marks". Anyway, cheaper than any computer screen, glasses, or phone wipes.
you must buy Iphone5
I just use a cloth/my sleeve... A glasses cleaner works too. Try getting a protective screen aswell.
Wash your hands.
Tee hee - I thought that might offend you, sorry but I couldn't help it! Surely though, computer screen wipes should sort it out - and computer / mobile phone stores should sell them they're fairly standard products.
Clean finger tips?