Does the iPod 4 and the iPhone 4 use the same charger?
to put it simply, yes.
Does an iPod shuffle use the same charger as an iPod touch?
no no no the iPod shuffle charger is too small
Does the iPhone 4S use the same charger as iPhone 3GS?
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.