what is your keitai like?

Hi, I was wondering what kind of features does your cellphone have? I'm sure it is amazing because Japan is always ahead of the US with cellphone technology.

Does anyone know if it is possible to take a JP phone with you back to the US and put it on an American contract like AT&T, Verizon or whatever.

The reason I ask is because I was thinking about getting an iphone, but since I'll be living in Japan I could probably get a far superior phone and take it home with me when I return to the US. Then sign it up over here.

よろしくお願いします！

First, you cannot use Japanese cellphones abroad.
They are locked to use with SIM cards of certain service providers, and it is usually impossible to break this lock.
And even if you somehow manage to unlock this, many of its features are useful only in Japan.

For example, a popular feature now is a function to receive
digitaly encoded TV broadcasts, which is called "one-seg" (abbreviation of "one segment"),
but this broadcasting method is only used in Japan so this function is useless abroad.

Maybe you find high-grade cameras with 3-5 mega pixel resolution interesting,
but it usually requires the original SIM card mentioned above,
and the photo management method to transfer it to PC or something is very poor.

The same problem is also true for music player function, and it is usually supposed to use a special converting/transfering software like iTunes but uses original format and utterly incompatible with other softwares.

From these viewpoints, I don't recommend you try to use Japanese cellphone back in your country.
But while I think iPhone are far better than Japanese one's,
remember that you cannot use iPhone purchased in Japan when you get back to your country.
It also has the SIM lock too.