I have a 3G and am jailbroken on 3.0 (or 3.0.1, definitely before the 3.1 update). I have a windows computer. Can I jailbreak to the new software (3.1.2)? How so? How about unlock? I am only interested in the unlock (or ability to unlock) for resale value, but I've read various threads that jailbreaking on 3.1.2 makes it impossible to later unlock. I want to be very careful with that since again, if/when I sell my phone, I want to unlock it and raise the value. Also, what are some of the downsides to jailbreaking to the new software?