Hey all my genius friends who are way more intelligent than me, So I have had awesome luck with selling my previous iPhones for a great price slightly before the new one comes out. Usually making enough to pay for the new phone...subsidized of course. Then I would just use an old phone for a month or so until I bought the new iPhone. Now my wife and I each have an iPhone 4. I have the original iPhone (nostalgia I guess) and I also have an old slider phone that my wife had before her iPhone. My question is regarding the sim cards. I understand that our iPhone 4's have a micro sim and the other phones have big sims. Can I just use an adapter like this one... http://www.amazon.com/gp/product/B003THJQVU/ref=ox_sc_act_title_3?ie=UTF8&smid=A3QF16EH69HELL and pop the sims into the older phones? Anything else I should know especially regarding the original iPhone (since it only runs IOS 3 or something)...or just tell me if I am way off altogether. Thanks a lot. Much appreciated.