Does the iPhone 4 for Sprint need a SIM card?

There was no SIM in my sprint Samsung Moment, so I'm just wondering: Do you need a SIM card for the Sprint iPhone 4 or not?

Yes every iPhone needs a Sim card. For an iPhone 4 you need a micro sim card.

No, Sprint does not use a SIM card because it is a CDMA provider. All the information about your number and stuff is directly programmed in the phone. Only GSM providers such as AT&T and T-Mobile uses SIM cards. CDMA providers like Sprint and Verizon does not.