I was gonna buy an iPhone 4 and I noticed some models have a sim slot and some don't, and this guy was saying that without a sim card in it that it won't even work as a phone just a glorified ipod? I can't imagine that the ones that don't have one that apple would even bother selling it as a phone if it doesn't even have a sim slot inside the phone to hold a sim card. i guess my question is, is it necessary to have a sim card? i would imagine not if some of the iphone 4's don't even have a sim slot but I just wanted to verify before I shelled out 200 dollars for it.