That's my question. I would like to obtain a 16g iphone 3g, firmware 2.1, so that I can unlock it and use an alternate sim in it. What would you do? Buy used form ebay or craig's list? Buy a new one from ebay or craig's list. If so, how best to determine a trustworthy seller--who would you trust more, someone selling their lightly used iphone or someone who seems to sell tons of them on ebay (who knows where they get tem).