I am in the exact same boat as many others with Straight talk and AT&T. I want to get a N4 for my Daughter's birthday and use Straight Talk. AT&T is the only carrier that works where she need service. This falling out between ATT and Walmart has really put a damper on this plan. There are other MVNOs out there that have ATT coverage, but I would really like the use ST as it is a little bit less expensive. If I can get my hands on a basic Straight Talk phone with an ATT sim in it that has not been activated, can the SIM be activated on a N4? I would cut it down if needed to a micro sim size. I am seeing in some discussions that ATT may lock the SIM to the phone's serial number. Just wondering if this was done when the phone shipped or when it was activated.