iPhone 4- Best unlock, backup, update?

[CatSitter]

Hey!
So I am interested in buying a used/newish iPhone 4, and then use it on the tmobile service. I understand that I will have to cut/ buy a microsim card and everything, but I have a few other questions...
1. What is the best unlock to use. I have a Windows Vista, if that makes any difference. I don't really want to have to pay anything to unlock the phone... also, what is the difference, if there is any, between jailbreak and unlock.
2. What if, there was a new version of iOS out, like (ex) 5.5 or something like that. How would I update my iPhone 4 to that new version while still being unlocked?
3. If I am unlocked, can I still backup my apps and music... to iTunes?
4. (kinda off topic) I use my iPod Touch 3g 8gb for music and such right now. How would I move all of my apps and music from the iPod Touch to the iPhone 4?
Thanks so much!

 

[Jmills87]

Firstly, welcome to the forums! What you want is an iPhone4 with an untethered jailbreak(meaning you want to find one that is running iOS 4.3.3 or lower). Anything higher than that will be a tethered jailbreak at this time which means whenever you reboot your phone you will have to connect your phone to your computer to boot it(although there is a semi-tether package that will let you use the basic functions of the phone if you aren't able to get to a computer to reboot).

Secondly, you need to get an iPhone with an unlockable baseband. The current basebands that are unlockable are 04.26.08 – 05.11.07 – 05.12.01 – 05.13.04 – 06.15.00 – 01.59.00. Those are the ONLY basebands that can be unlocked via software. If you get a phone with 04.10.01 you will have to buy a Gevey ULTRA SIM in order to unlock. If you get a phone with 04.11.08 you will not be able to unlock at all(not with software or hardware).

1. The best unlock to use is ultrasn0w(software) because it's free. Jailbreaking gives you root access to the phone and unlocking lets you use the phone on unofficial carriers. They are two completely separate things and unlocking is dependent on jailbreaking.

2. You would need to update using a custom firmware in order to preserve your baseband.

3. Yes, everything works the same as a stock phone in terms of syncing.

4. The apps and music are stored in your iTunes library, all you would do would be sync your iTunes library to the phone.

 

[CatSitter]

THANKS SO MUCH FOR REPLYING!!! Yea, these forums seem pretty cool...!
Ok, so is there ever going to be an untethered jailbreak for IOS 5? I am kinda confused about that. What if I never run out of battery and what not, tethered "could" work?
I am BEYOND confused with your second paragraph. To my understanding, all iPhones could be unlocked...? What does the base-band mean? How do you know what baseband your phone is? (I was going to buy craigslist or ebay)
1. Thanks, i was searching around and that DID seem the best.
2. So it is kinda like :

• Apple has ios 3, update to that
• apple has ios 4, update to that
• ios 5, update
• ...

Am I right with this understanding?
3.So everything works the same...! Great!! BUT! What about the the **special** apps that Apple doesn't support? Are they back-up too?
4. Thanks, just checking on that. Didn't want to have to get a new library for it all!!
Thanks so much!

 

[Jmills87]

Yes, eventually an untethered jailbreak will be released for iOS5. And no, not all iPhones can be unlocked, definitely not. Like I said, they MUST have an unlockable baseband(baseband is the modem firmware). You can find it in Settings>General>About you will have to ask the seller to tell you the baseband and firmware version.

I don't understand what you mean with #2.

3. There are Cydia apps that you can use to backup your 3rd party installations(xbackup, pkgbackup, aptbackup)

4. No problem

 

[CatSitter]

I got my #2 now... kinda answered it myself! !
Thanks, so if it is NOT unlockable, don't buy... gotcha!

 

[Jmills87]

Exactly! Good luck!