No, there are multiple sizes:
Yes. When you go on holiday or move supplier your SIM card changes to different supplier without the need to change the SIM card.
Yes
yes they do all have sim cards also on a different note the t-mobile phones accepts the cingular sim cards when unlocked and vice versa
SIM cards have generic sizes and basic functions. The difference lie in the frequencies that they operate on.
Verizon doesn't use SIM cards, so the Verizon iPhones presumably don't. All AT&T iPhones have a SIM card, though.
No, only Rzrs that worked on GSM networks have sim cards. Rzrs that worked on CDMA networks did not have a sim card slot.
Not all cell phones are compatible with SIM cards. Some only work with a contract, and you need to unlock the phone before you can use a SIM card.
No as they may be locked to a particular handset but if they are not you can move the SIM card to an other handset. Nokia do not have their own SIM cards they just lock the SIM card to their network via the SIM card settings.
Cellcom in Wisconsin does not have sim cards, wish they did. I have heard that you can get a sim card from them but non of their phones have a spot for sim cards.
All carriers handle SIM cards differently. AT&T requires SIM cards, but Verizon does not use them at all. Check your carrier's website for specific information.
Yes all iPhone have SIM cards although they are called micro sims (the gold chip only)
yea i have gotten several phones from att and used the same sim card for all of them, and kept the same phone number.
No, there are multiple sizes:FullMiniMicroNanoEmbedded
Yes, all sim cards conform to a standard size.