Drew-4s wrote hello i am thinking about getting an iphone 4 for christmas but i have tmboile can someone please explain to me what i would need to do and everything i should look for (im looking to buy a new one off of ebay)

I'll be happy to help you.

First you need to ring up tmobile, Or go in store and request a "Micro Sim".
the iPhone 4, and 4S require these.

You need to make sure the phone you buy obviously isn't

(i) Damaged
(ii) "no service" (it won't work in UK)
(iii) Been water damaged before
(iiii) Stolen.

I really hope i've helped, Pm me for anymore questions.