Do itouch and iPhone use the same charger?
IPhone 2g usb cable same as iPhone 3g charger?
Yes they will work
Does the iPhone 4S use the same charger as iPhone 3GS?
Does the iPod 4 and the iPhone 4 use the same charger?
to put it simply, yes.
Does the iPhone 4 use th same charger as older iPhones?
Yes, you can. You can only use FaceTime to video call another iPhone 4 and you must be connected to wi-fi to do this. The FaceTime call receiver must also be connect to wi-fi.