You will have to first get the phone unlocked.
No, T-mobile does not have the iPhone. AT&T has it though.
Yes, use your friends'.
T-Mobile does not have the Iphone only At&t does
There will not be an iPhone 4S for T-Mobile but you can get any iphone unlocked at unlockatt.com
In America, the two SIM-using GSM carriers are AT&T and T-Mobile. T-Mobile can only use it's EDGE network on an iPhone with a SIM Card needed.
In theory, yes. T-Mobile is actually the carrier for the iPhone in Germany. Keep in mind, however, that unlocking an iPhone completely voids its warranty, and if anything happens to it, the only recourse is to purchase a new iPhone. Apple will not service a broken iPhone if it is unlocked.
you can tbuy an iphone without at&t.....
The iphone4 is not coming out on t-mobile.
Yes, the iPhone 5 has been available on T-Mobile since February 2013.
AT&T SIM card is needed or if jailbroken/unlocked you can use T-MOBILE
No it is not. It is for AT&T unless you "jailbreak" and "unlock" an iphone. Instructions to do this can be found on the internet.
Yes, the GSM version of the iPhone is useable on the T-Mobile network, but it must first be unlocked. If you bring an At&t iPhone to a T-Mobile store, they will unlock it, and give you a proper sim card for it.