Can a tmobile sim card work with a at&t, cingular, or verizon wireless cell phone?

Unlocked phones that Only work with T-mobile Sim card.....Locked Phone cannot work with other GSM Network Sim card...If the Phone locked means you can unlock it using the unlock code...Get the Unlock code from here Classicunlocking.com
and Unlock it...Then use with AT&T,Cingular etc...But you can't use with CDMA Network like Sprint,Verizon ,boost etc....You can use only GSM Sim card.....