How do I convince my Mom to buy me a iPhone ?

..and dont tell me to wait

That really depends on a few things. How old are you, how have you been behaving lately, how old is your current phone if you have one, what's the last big thing she bought for you, etc. Personally, I think kids in their early teens are getting ruined by how addicting everything can get. If I see another commercial that ends with "friend us on facebook and follow us on twitter" I might vomit.

In conclusion, the best way to coerce your Mom into buying you an iPhone is to ask very politely. Try being super pleasant and helpful for a week straight before you ask, or something. I don't know your mother, so you're the only one with the real answer.

Personal experience.