iBart iapp's developer has let the cat out of the bag. The developer of the San Francisco metropolitan area transportation guide, iBart, would have seen his log files being returned under the reference 3.1...
Let us remind you the codes of each iPhone we have seen so far :
* iPhone 1,1 = iPhone Edge
* iPhone 1,2 = iPhone 3G, version I
* iPhone 2,1 = iPhone 3Gs
* iPhone 3,1 would then very likely be the iPhone 4G !!!