You don't need to be jailbroken now that the iPhone supports most carriers. The iPhone 4 is physically unable to switch from GSM to CDMA carriers anway.
No
No
if you bought if with orange or have jailbroken and unlocked it then yes is should work fine.
The Work on some Different Carriers.
YES it should although if its jailbroken/unlocked it will lock
a jailbreak is a process of adding applications that apple does not allow. I will hack your ipod touch/iphone and will add one of the following apps:Icy, Cydia, Rock, Installer, and Blacra1n. So if you do not know what you are doing , do not try it!!!! Jailbroken iphone and ipod rock, mine is jailbroken and i love it.
The two I've found so far are the Sky Go and Sky News apps.
Im not sure what you mean by installer but I assume your talking about apps. If you want to install apps you can download them from the app store and it will automatically install.Or you can download on itunes and sync to iPhone. If you have jailbroken you need to install 'installous' on cydia by adding hackulous as a source . Search how to install installous. For a normal iPhone that hasn't been jailbroken you don't need a extra program. But for jailbroken you need installous. I work for apple California i would know Also don't jailbreak it messes up your iPhone slows it down and voids your warranty.
If you are buying and iPhone in Canada, the iPhone supports the following carriers:BellMTSFidoRogersTelusVirgin MobileSasktelKoodoIf you are only traveling, you can purchase a Nano SIM card (if your iPhone is unlocked) from whichever carriers support them.
As of 6/17/13 T-Mobile has finally gotten the iPhone, and their merge with Metro PCS means that they will get the iPhone, too, because the two carriers will begin using each other's bandwidths. The reason this took so long is nicely explained below. The iPhone will be flashed soon because it was released for Verizon with the CDMA signal Verizon uses. I work at Metro PCS and i know for a fact that you can not use an iPhone with Metro PCS. Metro PCS is only allowed to use phones from Sprint and Verizon because they don't need a SIM card. iPhones need a SiM card, therefore, they will not work with Metro. While the above answer is basically correct that no current iPhone model (as of May 2010) can work with MetroPCS, the issue isn't related to use of a SIM card. Current iPhones contain only a GSM radio, but MetroPCS uses phones that contain a CDMA radio, so it's physically impossible to get any current iPhone to work with MetroPCS, or any other non-GSM carriers. Swapping SIM cards from CDMA phones, into an iPhone, doesn't somehow make the iPhone radio into a CDMA radio, since a phone's radio circuitry has nothing to do with the SIM card. To work on CDMA carriers, Apple would have to manufacture a new iPhone design that has a CDMA radio. The only other carrier in the US, besides AT&T, that the iPhone will work with, is T-Mobile, since they use GSM, but this requires unlocking your iPhone, which can often (though not always) be a tedious and complex process for people who aren't tech-savvy. ---
If your iPhone is unlocked, then yes, all carriers will work. But if it is locked to a certain carrier, then you will have to unlock it using a jailbreak.
yes jailbreaking your Iphone/Itouch will not ever break the devices. the only difference with jailbroken iphone is that you have access to "Cydia" which is an app store made for apps that are not allowed on the Apple App store. I highley suggest using GreenP0isen.