For those that purchased an "unlocked" 4s directly from Apple, which domestic U.S.A. carrier would you then be allowed to utilize if the 4S purchased directly from Sprint, VZW, and ATT are locked against them? I currently have a Sprint 4S. I knew purchasing it that I would not be using full functionality of the phone, since I do everything on my MB Air. I'm wasting a lot of money by paying for a data plan I don't use and need. Anyway, I am thinking about offloading this phone and plan to a relative. What I want to do is purchase an unlocked 4S phone, either through Sprint or Apple, and request to add it to an existing non-smartphone Sprint shared family plan, so I can use it strictly for phone use (most importantly, GSM International use, as I travel for work a lot). No need for text messaging and data. I can always use data via wi-fi as I don't have an urgency to reply to emails right away. Can this be done? Can I purchase an unlocked 4S through Sprint and add it as a second line to an existing non-smart phone plan since I am paying full price unlocked? Thanks!