Activated iPhone 3GS with 4.0.2 (old boot-rom): Is it unlockable?

[hoaindao]

Hello geniuses of the world. lol.
I just bought an iPhone 3GS with 4.0.2 on it. From what i've read through out the forum, it cannot be jailbroken without ShSH or downgrading it. However, could it be possible to unlock an activated phone? what i mean is that I have access to everything except voice calling. Is there a way to unlock the phone without having to jailbreak it? any comments is appreciated!!

[i.Annie]

It needs to be jb first