Looking to get a iPhone 4

[23nesnes]

I have a 2g Iphone running 3.1.2 and Im looking into getting a iPhone 4. Im just wondering if there is a unlock/jailbreak for it to use on tMobile? I tried to searh but all I keep coming up on is that it can only be done "teethered"??? Can someone please explain if its possible to unlock/jailbreak the iphone 4 and what it means that it can only be done "teethered"? I thought teethering was being able to use your iphone as a modem basically - i might be mistaken though. I originally unlock my first 2g so I do have an idea of doing this procedure.

[soulthoughts]

Tethered has two meanings. You're right on the first, it means you use your phone to get another device (i.e, laptop) on the internet via your phone's data.

It also means that every time you reboot your phone, you have to connect it to a computer to start up. This has to do with the jailbreak, not the unlock. You have to jailbreak to unlock.

We need more info on the iPhone 4 to determine if you can unlock.

[iYeow]

Only baseband of 1.59.00 for iphone 4 can be unlock. If you have IOS 4.1 or 4.2.1, the baseband cannot be unlocked. I suggest if you want an unlock, go get a factory unlock, less hassle but pay abit more, it is worth it if you are always travelling to other countries.
Software unlock , if you are not careful, you will locked up your iphone.