Want to try a new phone.

Hi,
This is my first post.
I am a long time US Cellular customer and I have been looking at getting a new phone. Through searching on ebay, I have seen quite a few phones that look interesting coming out of Hong Kong. The phones say they are GSM and CDMA compatible.

Is there such a thing as a CDMA Sim card I can put into one of these to basically turn it into a CDMA phone??

Any info would be greatly appreciated.
Thanks!

no and very few phones are GSM and CDMA so be careful about buying them and uscc will only activate phones that are uscc branded. only phones that have uscc software loaded on them are aloud on a uscc system.