Can you swap SIM cards between cell phones?

I have two Motorola cell phones, different models, one is unlocked, the other has Cingular service.

Can you swap SIM cards between cell phones?
most sim cards you can use in other phones but has to be same service. Your sim card mainly saves your numbers that you have programed to it so if you have the same service then you can use it in any phone.
Reply:If it's a cingular SIM card, yes, otherwise they will both only work in the unlocked phone.
Reply:you can try
Reply:You can swap the SIMs between phones no problem. I do it all the time because I have an unlocked phone I loan out to friends who are in-between phones. That darned phone has worked with about 12 diff SIMS so far.
Reply:YES U COULD IF THE ONE WITH THE PLAN HAD THE SIM CARD FIRST
Reply:yes you can but has to be phone that will take the sim cards other phones have different ones.
Reply:You sure can.