But just wondering if there's any way to use verizon CDMA iphone 4s on att since CDMA ones run on different modem firmware.
Can i upload a new IOS 5.0.1 from GSM section that would put the GSM modem firmware on it and use it on GSM carrier here in the US. Thx
No. GSM and CDMA don't just have different firmware, they use different radios. The hardware is different and incompatible. You can't load a GSM firmware onto a CDMA phone to convert it. There's no way to do that. Sorry.