iPhone 4 is iPhone3,1 and iPhone3,2
iPhone 4S is iPhone4,1
iPad 2 is iPad2,1 iPad2,2 and iPad2,3 depending on version (GSM etc)
iPad 3 is iPad3,1 iPad3,2 and iPad3,3 depending on version (GSM etc)
See Iphone secrets (scroll down to "internal product codes")
Another good source is:
everyiphone.com
