Oh, to clarify what I saw on the iPhone Fever about iOS fragmentation, iOS 3.1.2 & 3.1.3 were the maximum for the original iPhone and for the 3G & 3Gs iOS 3.1.2 & 3.1.3 were the easiest to jailbreak and carrier unlock so that explains why there are so many iPhones using those versions. Plus that graphic was designed not long after the iPhone 4 was released.