All of this "unlocked/jailbroken" stuff is not really clear to me. Here is my situation that I need advice from those of you that know about this stuff. My daughter has an iPhone on ATT. The phone works fine except for the speakers. $100 to fix - prob not bad. But now I am just learning about TMobile. Once her contract with ATT runs out, she could go to TMobile and get an unlimited everything plan for $50. That would save her alot of money. So, a guy at a wireless store(not ATT just independent guy) is telling me that she would be better off with the unlocked Motorola Defy than a jailbroken iPhone. He said apps are free for the Motorola Defy on some thing(sorry don't remember the name) whereas lots of the apps on iPhone have to be purchased. Well, that's not my main question. My main question is: if I buy her a jailbroken 3GS or 4G, is it possible to transfer it to TMobile and ALSO - is it true that that phone can have stuff locked down on it from ATT or Verizon so that the apps or other items on the phone would just stop working and then I would be out all the money I paid for the phone? My main interest is to get her a good smartphone to replace her messed up iPhone AND get it so she can save money on her phone bill. Oh - one more thing: The guy also said on the jailbroken iPhone, she could have trouble with the wi-fi not working. Is that true, and if so, can you explain to me why?