I'm selling my 16GB iPhone 3GS which is unlocked for T-Mobile or can be used with AT&T. It is currently on iOS 4.3.3 but I can put it to iOS5 if you'd like (tethered jailbreak). There's minor scuffles on the edges but the screen is scratch-free and always has had a protector. Price is firm, can meet on Stanford campus or in Mountain View.