I just switched from ATT to Verizon and also got a new iPhone 4s (traded in the 3Gs I had for 2 years). After I synced it at home to put all my apps, music, etc. back on it. It came up with a message on the phone's screen which said no SIM card was installed (or not found). The phone seems to be working fine. I thought it needed a SIM card to work? I really don't know what a SIM card is but I remember when I bought the first one 2 years ago hearing something about them. Can anyone tell me if I should be worried or what I can do to fix the issue? (I am going to call Verizon tomorrow but wanted ask the community as well).
Contact Verizon or the Apple Store where you got it. Verizon is a CDMA carrier and does not use SIM cards. There have been a few reports of this with new Verizon phones. They should be able to resolve it for you.