Phrase translation japanese-english?

Question:

Konbanwa minna-san!
Well...yes,i'm trying to learn japanese.Right now,i need help with just one phrase "Keitai wa,mou keitai denwa ja nai".I heard it in a commercial,and i tried to translate it.Well.....i know what "keitai denwa" means,so i know "keitai" too.I MIGHT know "ja nai".....but i'm not sure of it(anyway,is it "ja nai" or "janai"?).And now "MOU" that's actually the one that confuses me.I've seen it used with various meanings and i'm not sure about what could the maning be here.
No matter how i look at this sentence,i can't understand it at all and it's getting really REALLY frustrating!
So,domo arigato for helping me!

Answer:

If translated literally, it's like: "A cellular is no longer a cellular phone."

It's an ad copy and what it implicates is that cellphones today come with so many different features that making calls is only just one of the many uses they are capable of.

"mou" is "no longer"
"janai" is a colloquial form of "dewa arimasen" "dewa nai", not.