Well...
As of April 2011 the American iPhone is compatible with:
**can also use T-Mobile's slower EDGE network with a SIM Card for those who are desparate to own these quality devices.
***Once again, these are only the American carriers.
Right now you can get the iPhone through AT&T and T-Mobile. All you do is order a sim card and you can use T-Mobile on your iPhone. WHen it will be able through other carriers some people say will be in January when the iPhone goes to Verizon, and October when it goes to Sprint.
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.
speculation is the end of this year I am hearing in July of next year TMobile will start offering this service. you could also buy an unlocked iphone to use on other carriers
The iPhone 3GS is only available on AT&T, but newer models are available on more carriers.
I don't believe any carriers still sell the iPhone 3GS or older, especially considering they offer the iPhone 4 now for free (with contract).
You can get an iPhone at the Apple store, through carriers, or online or "brick-and-mortar" retailers.
The Work on some Different Carriers.
The iPhone will always be available on AT&T, but since 2010 they expanded to other carriers such as Verizon (2010), Sprint (2011), and T-Mobile (2013).
no, they are the exact same phone just with different carriers.
Here's a simple fix: SWITCH CARRIERS!!!!!!!!!
I think PCworld or Macworld did mention somewhere that apple had plans to expand their device to other carriers... but that will be some time.
Probably not, because I don't think there are any carriers that the iPhone supports in Bangladesh.