I have an iPhone 4 (Verizon), which is about to be out of contract (in October). However, I don't want to renew my contract w/ Verizon, because I'm going to be traveling to South America indefinitely (starting Oct 1st). So getting a subsidized 4S/5 is not really an option. From what I understand, I can't have my iPhone 4 unlocked since Verizon's iPhone 4 model doesn't have a SIM card. So, I need to get at least a 4S (or possibly an earlier model). I think what I'm looking to do is buy an unlocked 4S/3GS that I can pop a local SIM card in. (Aside: I was looking at TruPhone, but can't find that many reviews of it online. Does anyone have any experience with this company? http://truphone.com) If I go that route, what do I need to look out for? I see a lot of "factory unlocked" phones for sale on Craigslist, are these legit? I also want to sell my iPhone 4 then (it's 32GB). Should I get it "factory unlocked" to do that (I see a lot of those services on CL)? Or should I call Verizon and have them unlock it? (Again, not sure if that's even a thing since the 4 doesn't have a SIM card.) I would be looking to spend as little money (net new phone - old phone) as possible. Thanks for any input anyone has!