Does the LTE Rezound have GSM radios? I don't think its possible. But I could be wrong. Although, Straight Talk now supports VZW, you may be able to get a SIM card for it.
Sent from the red headed stepchild of the Nexii.
Make sure you use the AT&T SIM, at least for now. T-Mobile's HSPA+ network currently operates on the 2100 MHz band, while the Rezound works on 1900 MHz, so I believe you'd only get Edge speeds on T-Mobile. They are migrating their HSPA+ network over to 1900 MHz, but that won't won't be rolling out nationwide until next year. AT&T's HSPA+ network operates on 1900 MHz, so I "think" the rezound should get full data.
I'm kinda nervous to do this. I've been reading that people have trouble with getting text messages to send. And also do I choose the first choice on the pic attachedhttp://img694.imageshack.us/img694/8558/36436042.png when ordering my sim card?